Drawn from the papers, not from records — 19 October 2026

Eleven ACM papers as discourse graphs, positive and negative

Eleven papers published by ACM under CC BY, chosen as a mix: three negative results, one null result, two mixed, five positive, across programming languages, software engineering, human-computer interaction, data mining and security. The three security papers are from the group of Elisa Bertino at Purdue University, ACM’s President since July 2026, and include an attack paper, whose negative result is for a security assumption rather than for a method. Each is drawn from its version of record as a question, a hypothesis, the experiments that addressed it, the results they produced and the edge each result earns. Every result names where in the paper it comes from.

The graphs on this page are drawn from the papers, not from Negative-Results Records: the extraction read each full text and recorded a locator and a short quote for every finding. The eight graphs at portolansoft.com/graphs are drawn from records. All graphs · The SAGE set · The PINN set · The pilot

How to read these graphs

A discourse graph breaks a piece of research into typed one-sentence nodes and draws how they bear on one another. The grammar is that of Discourse Graphs (Chan and Akamatsu). Read each graph left to right: a question, the experiments that addressed it, the results they produced, and the hypothesis every result is drawn against.

QUE Question
What the work set out to answer.
HYP Hypothesis
The answer the authors expected. Every result earns one edge against it.
EXP Experiment
One attempt at the question: a trial arm, an assay, a survey, an analysis.
RES Result
One finding from an experiment, with where in the source it comes from.
ISS Issue
An open question or untried branch the work leaves for someone else.
addresses
An experiment addresses the question.
produces
An experiment produces a result.
supports
A positive result that backs the hypothesis.
opposes
A negative result that counts as evidence against the hypothesis, or a refutation of an earlier claim.
informs
A partial or mixed result that bears on the hypothesis without settling it.
consistent with
A negative or inconclusive result that does not count either way: no positive control passed, or there is no sensitivity or power statement, so the absence of an effect cannot be told from a measurement that failed.
relation
A thin dotted line: a link the source itself states between two experiments, such as one being derived from another.

A dashed box marks a result the rule above counts as uninformative, or an issue. In the drawing, click a node to jump to its text below.

The edge rule, translated for computer science

The key above is written for laboratory and clinical papers, where a negative counts only with a passing positive control and a stated sensitivity. Computer-science papers have equivalents rather than the same things, and the extraction used them. In a security paper the hypothesis of an attack is the property the target is assumed to have, so a demonstrated attack with a measured effect opposes it; a defence is drawn like any other method, against its own claim. In a user study or a field study the control is a control condition or a comparison group, and the sensitivity statement is the reported test with its sample size and interval. In a benchmark the control is a baseline that was tuned or reproduced, not a number copied from another paper, and the sensitivity statement is variance over runs or seeds, an interval, or a significance test. A null or worse result is drawn as opposing the hypothesis only when those hold; otherwise it is drawn as merely consistent with it. For a paper whose point is a null or negative result, the hypothesis is the expectation it set out to test, so that the null opposes it. The brief the extraction followed is kept with the JSON for each graph.

How the eleven were chosen

From ACM’s catalogue as OpenAlex indexes it, articles whose version of record is CC BY, which in practice means the journals and the Proceedings of the ACM series rather than conference volumes. Within that, a deliberate mix rather than a citation ranking: the most-cited CC BY papers at ACM are surveys, perspectives and graphics methods, and a page meant to show negatives alongside positives needs papers of both kinds. The negatives were found by searching titles and abstracts for the words papers use when a result goes the wrong way; the positives are highly cited empirical papers from the same venues. Each licence was checked against Crossref’s version-of-record field, and every text carries ACM’s own CC BY line. The three security papers were added a day later by a different route: Elisa Bertino’s author record in OpenAlex, filtered to ACM and to CC BY on the version of record, gives five articles and one survey; the three articles with an experiment that could have gone either way were taken, the survey and the two remaining articles (a network-measurement index, a privacy-preserving crowdsourcing optimiser) were not. For one of the three, Crossref’s licence field still points at ACM’s copyright policy while the version of record itself carries the CC BY line; the page goes by the version of record. Citation counts are forward citations (works citing the paper, OpenAlex, 19 October 2026).

The eleven

Cited by: works citing the paper, OpenAlex, 19 October 2026. All eleven are CC BY 4.0 on the version of record.
AreaPaperVenueCited byWhat it is
Programming languagesBarrett, Bolz-Tereick, Killick, Mount & Tratt, Virtual machine warmup blows hot and cold. 10.1145/3133876Proc. ACM Program. Lang. 1, OOPSLA, 2017112A negative result: the assumption that virtual machines warm up to a steady state, tested across VMs and benchmarks.
Marcozzi, Tang, Donaldson & Cadar, Compiler fuzzing: how much does it matter?. 10.1145/3360581Proc. ACM Program. Lang. 3, OOPSLA, 201941A mixed result: how often fuzzer-found compiler bugs affect real programs, against user-reported and verification-found bugs.
Software engineeringOuyang, Zhang, Harman & Wang, An Empirical Study of the Non-Determinism of ChatGPT in Code Generation. 10.1145/3697010ACM Trans. Softw. Eng. Methodol. 34(2), 2025250A negative result for a working assumption: one request is not representative, and temperature zero does not make it so.
Yuan, Liu, Ding, Wang, Chen, Peng & Lou, Evaluating and Improving ChatGPT for Unit Test Generation. 10.1145/3660783Proc. ACM Softw. Eng. 1, FSE, 2024164A mixed result: generated tests often fail to compile or pass, but the ones that pass resemble human tests; then a method that improves them.
Human-computer interactionChuai, Tian, Pröllochs & Lenzini, Did the Roll-Out of Community Notes Reduce Engagement With Misinformation on X/Twitter?. 10.1145/3686967Proc. ACM Hum.-Comput. Interact. 8, CSCW2, 202465A null result: no evidence that the intervention reduced engagement with misleading posts, with an explanation of why.
Weber, Brandmaier, Schmidt & Mayer, Significant Productivity Gains through Programming with Large Language Models. 10.1145/3661145Proc. ACM Hum.-Comput. Interact. 8, EICS, 202463A positive result from a controlled user study of code assistants.
Draxler, Werner, Lehmann, Hoppe, Schmidt, Buschek & Welsch, The AI Ghostwriter Effect: When Users do not Perceive Ownership of AI-Generated Text but Self-Declare as Authors. 10.1145/3637875ACM Trans. Comput.-Hum. Interact. 31(2), 2024177A positive result with a null inside it: the effect holds in two studies, and personalisation does not change it.
Data miningLines, Taylor & Bagnall, Time Series Classification with HIVE-COTE: The Hierarchical Vote Collective of Transformation-Based Ensembles. 10.1145/3182382ACM Trans. Knowl. Discov. Data 12(5), 2018332A positive result that starts with a negative one: two convolutional networks lose to the existing ensemble before the new ensemble beats it.
SecurityGroen, DiValerio, Karim, Villa, Zhang, Bonati, Polese, D’Oro, Melodia, Bertino, Cuomo & Chowdhury, TIMESAFE: Timing Interruption Monitoring and Security Assessment for Fronthaul Environments. 10.1145/3775060ACM Trans. Priv. Secur. 29(1), 20252A negative result for a security assumption, then a defence: timing attacks on the Open RAN fronthaul take a base station down, and a monitor detects them.
Huang, Lee, Kundu, Chen, Mudgerikar, Li & Bertino, ARIoTEDef: Adversarially Robust IoT Early Defense System Based on Self-Evolution against Multi-step Attacks. 10.1145/3660646ACM Trans. Internet Things 5(3), 202411A positive result that starts with a failure: the infection detector is fully evaded by a white-box attack before self-evolution recovers most of its recall.
Huang, Lin, Chen & Bertino, Dimensional Robustness Certification for Deep Neural Networks in Network Intrusion Detection Systems. 10.1145/3715121ACM Trans. Priv. Secur. 28(3), 20255A positive result: a certification method for intrusion-detection models against randomized-smoothing baselines, with certified and empirical robustness.

VM warmup rarely reaches a steady state of peak performance (Proc. ACM Program. Lang. OOPSLA, 2017)

Programming languages · Proc. ACM Program. Lang. 1, OOPSLA, 2017

A negative result: the assumption that virtual machines warm up to a steady state, tested across VMs and benchmarks.

Read left to right. The question (QUE) is addressed by 5 experiments (EXP), each producing results (RES), and each result bears on the hypothesis (HYP). 0 support it, 4 oppose it, 5 inform it. Issues (ISS) hang below: what the paper leaves open.

HYP, in the authors’ words (Section 1 Introduction): “H1 Small, deterministic programs reach a steady state of peak performance.”

Discourse graph of VM warmup rarely reaches a steady state of peak performance (Proc. ACM Program. Lang. OOPSLA, 2017) que addresses main-warmup-experiment que addresses hardware-os-comparison que addresses gc-jit-instrumentation que addresses georges-heuristic-comparison que addresses run-length-sensitivity main-warmup-experiment produces good-pairs-30-to-43-percent good-pairs-30-to-43-percent opposes hyp main-warmup-experiment produces bad-inconsistency-dominant bad-inconsistency-dominant opposes hyp main-warmup-experiment produces process-execution-classes process-execution-classes opposes hyp main-warmup-experiment produces steady-state-timing-uneven steady-state-timing-uneven opposes hyp hardware-os-comparison produces h1-failure-replicates-across-machines h1-failure-replicates-across-machines informs hyp gc-jit-instrumentation produces gc-jit-explain-only-some gc-jit-explain-only-some informs hyp georges-heuristic-comparison produces georges-false-steady-states georges-false-steady-states informs hyp run-length-sensitivity produces iteration-truncation-nonmonotonic iteration-truncation-nonmonotonic informs hyp run-length-sensitivity produces process-executions-diminishing-returns process-executions-diminishing-returns informs hyp hardware-os-comparison confirms main-warmup-experiment: The same data split by machine shows the failure of H1 reproduces on two Linux machines with different hardware; OpenBSD differs mainly because three VMs could not run there. gc-jit-instrumentation informs main-warmup-experiment: Attempts to explain the slowdown and no-steady-state executions found in the main experiment; explains only some of them. georges-heuristic-comparison comparedWith main-warmup-experiment: The prior standard heuristic, run on the same data, reports steady states where changepoint analysis finds none, which is why earlier work saw H1 as holding. run-length-sensitivity informs main-warmup-experiment: Tests whether the 2000-iteration and 30-execution choices of the main experiment were necessary for its conclusions. ISS · open questions and untried branches this path leaves behind QUE · refuted Do small, deterministic microbenchmarks on JIT-compiling VMs warm up and reach a steady state of peak performance, as VM benchmarking methodologies assume? Do small, deterministic microbenchmarks on JIT-compiling VMs warm up and reach a steady state of peak performance, as VM benchmarking methodologies assume? HYP H1: small, deterministic programs run on JIT-compiling VMs warm up and then reach a steady state of peak performance (the traditional two-phase view of VM execution). H1: small, deterministic programs run on JIT-compiling VMs warm up and then reach a steady state of peak performance (the traditional two-phase view of VM execution). EXP · refuted 6 CLBG/Richards microbenchmarks on 7 VMs plus C on 3 machines, 30 process executions x 2000 in-process iterations each (3660 executions), classified by… 6 CLBG/Richards microbenchmarks on 7 VMs plus C on 3 machines, 30 process executions x 2000 in-process iterations each (3660 executions), classified by changepoint analysis RES · refuted Only 30.0-43.5% of VM-benchmark pairs (depending on machine and OS) consistently reach a steady state of… Only 30.0-43.5% of VM-benchmark pairs (depending on machine and OS) consistently reach a steady state of peak performance, and none of the seven VMs consistently does so. RES · refuted The largest class is 'bad inconsistent' (43.5% of pairs on Linux1240v5, 45.7% Linux4790, 70.0% OpenBSD4790): the same… The largest class is 'bad inconsistent' (43.5% of pairs on Linux1240v5, 45.7% Linux4790, 70.0% OpenBSD4790): the same benchmark, VM and machine shows more than one behaviour. RES · partial Per process execution, 72.4% (Linux1240v5), 74.7% (Linux4790) and 86.1% (OpenBSD4790) show 'good' warmup… Per process execution, 72.4% (Linux1240v5), 74.7% (Linux4790) and 86.1% (OpenBSD4790) show 'good' warmup; the rest slow down or never reach a steady state. RES · partial Time to steady state is uneven: VMs stabilise in 10 or fewer iterations or take hundreds (JRuby+Truffle binary… Time to steady state is uneven: VMs stabilise in 10 or fewer iterations or take hundreds (JRuby+Truffle binary trees median 1082 iterations, 2219.59 s); slow warmers tend to have slow steady states. EXP · positive H2 test: same experiment on Linux1240v5 (Xeon E3-1240 v5, Debian 8), Linux4790 (i7-4790, Debian 8) and OpenBSD4790 (i7-4790, OpenBSD 6.0), comparing class… H2 test: same experiment on Linux1240v5 (Xeon E3-1240 v5, Debian 8), Linux4790 (i7-4790, Debian 8) and OpenBSD4790 (i7-4790, OpenBSD 6.0), comparing class proportions RES · positive H1's failure reproduces across machines: Linux1240v5 and Linux4790 proportions differ by a few percent; OpenBSD4790 ha… H1's failure reproduces across machines: Linux1240v5 and Linux4790 proportions differ by a few percent; OpenBSD4790 has 70.0% bad inconsistent pairs, partly as JRuby+Truffle is absent. EXP · inconclusive H3 test: HotSpot and PyPy run in Krun 'instrumentation mode' recording JIT and GC time per in-process iteration, to see whether these explain non-warmup proces… H3 test: HotSpot and PyPy run in Krun 'instrumentation mode' recording JIT and GC time per in-process iteration, to see whether these explain non-warmup process executions RES · inconclusive GC and JIT compilation plausibly explain some non-warmup executions (Figures 6 and 7) but not many others (Figure 8)… GC and JIT compilation plausibly explain some non-warmup executions (Figures 6 and 7) but not many others (Figure 8); with few instrumented results H3 is left undecided. EXP · positive Georges et al. 2007 coefficient-of- variance steady-state heuristic (threshold 0.01) applied to the same 3660 process executions and compared… Georges et al. 2007 coefficient-of-variance steady-state heuristic (threshold 0.01) applied to the same 3660 process executions and compared with the changepoint classification RES · positive The Georges et al. heuristic finds a steady state in 78.1% of the process executions classified as no steady… The Georges et al. heuristic finds a steady state in 78.1% of the process executions classified as no steady state, so the traditional method would have wrongly affirmed H1 in those cases. EXP · partial Run-length sensitivity on Linux1240v5: executions truncated to n in {10..1990} iterations, and 1000 bootstrap samples of n in {2..30} process executions, vs… Run-length sensitivity on Linux1240v5: executions truncated to n in {10..1990} iterations, and 1000 bootstrap samples of n in {2..30} process executions, vs full 2000 x 30 RES · partial Overall similarity to the full run is 85% at n=700 in-process iterations but 78% at n=900, with a kink at 1000-1300… Overall similarity to the full run is 85% at n=700 in-process iterations but 78% at n=900, with a kink at 1000-1300 caused by JRuby+Truffle slowing down around iteration 1050. RES · partial At n=2 process executions classification quality is poor; diminishing returns begin at n=6, 10 process executions giv… At n=2 process executions classification quality is poor; diminishing returns begin at n=6, 10 process executions give very similar results and 15 all but identical results to 30. ISS · open-question Cause of many non-warmup process executions is unknown: GC and JIT events explain only some on HotSpot and PyPy, and other VMs lack usable… Cause of many non-warmup process executions is unknown: GC and JIT events explain only some on HotSpot and PyPy, and other VMs lack usable instrumentation. ISS · open-question Which of Krun's many controls matter most for a reliable experiment is open; untangling the interlocking combinations is estimated to need many months of… Which of Krun's many controls matter most for a reliable experiment is open; untangling the interlocking combinations is estimated to need many months of running time. ISS · open-question Whether some property of binary trees, fasta and Richards makes bad inconsistency more likely is unresolved; they share no obvious characteristic. Whether some property of binary trees, fasta and Richards makes bad inconsistency more likely is unresolved; they share no obvious characteristic. ISS · untried Untried: more distinct hardware (non-x86), systematic tests of whether rebuilding VMs affects warmup, and sampling the ASLR space with Stabilizer… Untried: more distinct hardware (non-x86), systematic tests of whether rebuilding VMs affects warmup, and sampling the ASLR space with Stabilizer, which could not be built.
  • supports positive finding
  • opposes a null, worse or failed result against a control or tuned baseline, with a reported test, interval or variance to show it is real
  • informs bears on the question without deciding the hypothesis
  • thin grey a relation between two experiments
Nodes, in reading order. Sources: Barrett, Bolz-Tereick, Killick, Mount & Tratt 2017, 10.1145/3133876; version of record from the ACM Digital Library, CC BY 4.0, read in full on 19 October 2026.
NodeTextTypeOutcomeEdge
EXP6 CLBG/Richards microbenchmarks on 7 VMs plus C on 3 machines, 30 process executions x 2000 in-process iterations each (3660 executions), classified by changepoint analysis
At most 43.5% of VM-benchmark pairs consistently reach a steady state of peak performance; none of the seven VMs does so consistently.
controlled benchmark measurement study with automated changepoint classificationrefuted
RESOnly 30.0-43.5% of VM-benchmark pairs (depending on machine and OS) consistently reach a steady state of peak performance, and none of the seven VMs consistently does so.
'good' VM-benchmark pairs (flat, warmup or good inconsistent) = 43.4% Linux1240v5, 43.5% Linux4790, 30.0% OpenBSD4790; 30 process executions x 2000 in-process iterations per pair; 3660 process executions, 7,320,000 in-process iterations in total
Section 1 Introduction; Section 5 Results, Table 1 · “Only 30.0-43.5% (depending on the machine and OS combination) of VM, benchmark pairs consistently reach a steady state of peak performance.”
refuted
informative
opposes HYP
RESThe largest class is 'bad inconsistent' (43.5% of pairs on Linux1240v5, 45.7% Linux4790, 70.0% OpenBSD4790): the same benchmark, VM and machine shows more than one behaviour.
Table 1, VM-benchmark pairs: bad inconsistent 45.7% / 43.5% / 70.0%; slowdown 6.5% / 6.5% / 0.0%; no steady state 4.3% / 6.5% / 0.0% (Linux4790 / Linux1240v5 / OpenBSD4790); 30 process executions per pair
Section 5 Results, Table 1 and Figure 4 · “the biggest proportion by far is 'bad' inconsistent at 43.5% (Linux4790 has very similar proportions).”
refuted
informative
opposes HYP
RESPer process execution, 72.4% (Linux1240v5), 74.7% (Linux4790) and 86.1% (OpenBSD4790) show 'good' warmup; the rest slow down or never reach a steady state.
Table 1, process executions: flat 26.4% / 20.9% / 34.0%; warmup 48.3% / 51.5% / 52.1%; slowdown 16.7% / 17.9% / 11.1%; no steady state 8.7% / 9.6% / 2.8% (Linux4790 / Linux1240v5 / OpenBSD4790); 3660 process executions total
Section 5 Results, Table 1 · “43.4% of VM, benchmark pairs have consistently 'good' warmup (i.e. are flat, warmup, or good inconsistent) and 72.4% of all process executions have 'good' warmup”
partial
informative
opposes HYP
RESTime to steady state is uneven: VMs stabilise in 10 or fewer iterations or take hundreds (JRuby+Truffle binary trees median 1082 iterations, 2219.59 s); slow warmers tend to have slow steady states.
Table 2 (Linux1240v5): JRuby+Truffle binary trees steady iter (#) median 1082.0 (5%-95% 999.0, 1232.5), steady iter (s) 2219.59 (2039.304, 2516.021); JRuby+Truffle fannkuch redux 1016.5 (999.0, 1023.1); HotSpot binary trees 7.0 (7.0, 53.5); medians over 30 process executions
Section 5 Results, Table 2; Section 9 (second suggestion) · “VMs seem to mostly either reach a steady state quickly (often in 10 or fewer in-process iterations) or take hundreds of in-process iterations.”
partial
informative
opposes HYP
EXPH2 test: same experiment on Linux1240v5 (Xeon E3-1240 v5, Debian 8), Linux4790 (i7-4790, Debian 8) and OpenBSD4790 (i7-4790, OpenBSD 6.0), comparing class proportions
Two Linux machines on different hardware give proportions within a few percent of each other; OpenBSD differs, partly because three VMs could not run there.
replication across hardware and operating systemspositive
RESH1's failure reproduces across machines: Linux1240v5 and Linux4790 proportions differ by a few percent; OpenBSD4790 has 70.0% bad inconsistent pairs, partly as JRuby+Truffle is absent.
Table 1: good pairs 43.5% Linux4790 vs 43.4% Linux1240v5 vs 30.0% OpenBSD4790; bad inconsistent 45.7% vs 43.5% vs 70.0%; OpenBSD4790 runs a subset (no Graal, HHVM, JRuby+Truffle); 30 process executions x 2000 iterations per pair on each machine
Section 5 Results, Table 1; Section 3.4 · “(both running Linux but on quite different hardware) are comparable, with the relative proportions of all measures being only a few percent different”
positive
informative
informs HYP
EXPH3 test: HotSpot and PyPy run in Krun 'instrumentation mode' recording JIT and GC time per in-process iteration, to see whether these explain non-warmup process executions
Some slowdowns correlate with GC (a suspected PyPy memory leak) or JIT events, but many do not; the authors could neither validate nor invalidate H3.
instrumented explanatory follow-upinconclusive
RESGC and JIT compilation plausibly explain some non-warmup executions (Figures 6 and 7) but not many others (Figure 8); with few instrumented results H3 is left undecided.
no counts reported; qualitative correlations only, on 2 VMs (HotSpot, PyPy); the authors state they make no claim of causation
Section 5.2 The Effects of Compilation and GC, Figures 6-8 · “Whilst some non-warmups are plausibly explained by GC or JIT compilation events, many are not, at least on HotSpot and PyPy.”
inconclusive
uninformative
informs HYP
EXPGeorges et al. 2007 coefficient-of-variance steady-state heuristic (threshold 0.01) applied to the same 3660 process executions and compared with the changepoint classification
The widely used heuristic reports a steady state for most process executions that changepoint analysis classifies as having none.
comparison against prior detection heuristicpositive
RESThe Georges et al. heuristic finds a steady state in 78.1% of the process executions classified as no steady state, so the traditional method would have wrongly affirmed H1 in those cases.
78.1% of 'no steady state' process executions reported as steady by the Georges et al. heuristic at coefficient-of-variance threshold 0.01; in virtually all cases where changepoint analysis found a steady state the heuristic did too
Section 8 Related Work · “it also finds steady states for 78.1% of the process executions we classify as no steady state, including Figure 2.”
positive
informative
informs HYP
EXPRun-length sensitivity on Linux1240v5: executions truncated to n in {10..1990} iterations, and 1000 bootstrap samples of n in {2..30} process executions, vs full 2000 x 30
Fewer process executions (10-15) would have given nearly identical results, but fewer in-process iterations behaves non-monotonically because of VM effects around iteration 1050.
convergence study / sample-size sensitivitypartial
RESOverall similarity to the full run is 85% at n=700 in-process iterations but 78% at n=900, with a kink at 1000-1300 caused by JRuby+Truffle slowing down around iteration 1050.
overall similarity (all three characteristics statistically equivalent) = 85% at n=700, 78% at n=900 in-process iterations, Linux1240v5 data, truncation n in {10,20,...,1990}; sliding window and steady-state length scaled in proportion
Section 9.1.1 In-process iterations, Figures 9 and 10 · “the 'overall' similarity is better at n = 700 (85%) than it is at n = 900 (78%).”
partial
informative
informs HYP
RESAt n=2 process executions classification quality is poor; diminishing returns begin at n=6, 10 process executions give very similar results and 15 all but identical results to 30.
1000 bootstrapped sample sets per VM-benchmark pair for each n in {2,...,30}, Linux1240v5; no percentages stated in text beyond Figure 11
Section 9.1.2 Process executions, Figure 11 · “We would have had very similar results to our final experiment with just 10 process executions and all but identical results with 15 process executions.”
partial
informative
informs HYP
  • ISS Cause of many non-warmup process executions is unknown: GC and JIT events explain only some on HotSpot and PyPy, and other VMs lack usable instrumentation. (open-question · Section 5.2)
  • ISS Which of Krun's many controls matter most for a reliable experiment is open; untangling the interlocking combinations is estimated to need many months of running time. (open-question · Section 10 Conclusions)
  • ISS Whether some property of binary trees, fasta and Richards makes bad inconsistency more likely is unresolved; they share no obvious characteristic. (open-question · Section 5 Results)
  • ISS Untried: more distinct hardware (non-x86), systematic tests of whether rebuilding VMs affects warmup, and sampling the ASLR space with Stabilizer, which could not be built. (untried · Section 7 Threats to Validity)

Extraction notes: Text appears to be the version of record: Proc. ACM Program. Lang. Vol. 1, OOPSLA, Article 52, October 2017, CC BY 4.0, with a footnote that updates live at arXiv 1602.00602. The appendices the paper refers to (Appendix A DaCapo/Octane, Appendix C curated plots, Tables 8 and 9) are NOT in the text file, which ends at the references, so nothing from them is used. Table 1 in the extraction lost the classifier icons; the row order (flat, warmup, slowdown, no steady state, good inconsistent, bad inconsistent) is inferred from the caption key order and checked against the prose figures (43.4%/72.4% Linux1240v5, 43.5%/74.7% Linux4790, 30.0%/86.1% OpenBSD4790, and 6.5%/6.5%/43.5% for slowdown/no steady state/bad inconsistent on Linux1240v5), which match; the specific slowdown and no-steady-state percentages for Linux4790 and OpenBSD4790 and the per-class process-execution percentages are read from that inferred order. Table 2 is heavily garbled by the PDF extraction (columns interleaved across benchmarks); the JRuby+Truffle binary trees (1082.0) and fannkuch redux (1016.5) and HotSpot binary trees (7.0) steady-iter values are read from rows whose labels are adjacent in the text and are moderate confidence only; the inconsistent-pair counts such as (27,3) could not be attributed to classes because the icons are lost. The paper says 'seven VMs' but lists eight language implementations: GCC 4.9.3 (C, not a VM) plus Graal 0.18, HHVM 3.15.3, JRuby+Truffle 9.1.2.0, HotSpot 8u112b15, LuaJIT 2.0.4, PyPy 5.6.0, V8 5.4.500.43. Benchmarks: binary trees, spectralnorm, n-body, fasta, fannkuch redux (CLBG) and Richards. Skipped: Graal, HHVM, JRuby+Truffle on OpenBSD; fasta on JRuby+Truffle (crashes); Richards on HHVM (too slow). The number of VM-benchmark pairs per machine is not stated explicitly in the text; only the totals 3660 process executions and 7,320,000 in-process iterations are given. The outcomeClass 'positive' on hardware-os-comparison refers to the paper's own H2 (moderately different hardware/OS has little effect), which the authors call 'a somewhat clear validation'; its valence against H1 is my reading (informs). The outcomeClass 'positive' on georges-heuristic-comparison means the comparison showed what the authors set out to show (that the prior heuristic misreports steady states); it is not a result about H1 and its 'informs' valence is my reading. The 'uninformative' tag on the H3 finding is my reading of the authors' statement that they feel unable to validate or invalidate H3 because of few results. Valence 'opposes' on main-experiment findings is justified because the baseline is the hypothesis itself, measured with 30 process executions per pair, outlier handling, and bootstrapped 99% confidence intervals, in a controlled environment designed to favour H1. Minor inconsistencies: Figure 10 caption says 'TruffleRuby' where the text says JRuby+Truffle; Figures 9 and 11 captions refer to 'Linux1240v5's results (seen in Figure 2)', which appears to mean Table 2. Startup-time results (Section 6, 200 process executions per VM, LuaJIT about 5x and JRuby+Truffle about 3500x slower than C) were omitted as not bearing on H1. The abstract gives the headline as 'at most 43.5%' while the introduction gives the range 30.0-43.5%; both are used.

Do fuzzer-found miscompilation bugs matter for real-world applications? (Proc. ACM Program. Lang., OOPSLA, 2019)

Programming languages · Proc. ACM Program. Lang. 3, OOPSLA, 2019

A mixed result: how often fuzzer-found compiler bugs affect real programs, against user-reported and verification-found bugs.

Read left to right. The question (QUE) is addressed by 5 experiments (EXP), each producing results (RES), and each result bears on the hypothesis (HYP). 2 support it, 1 oppose it, 8 inform it. Issues (ISS) hang below: what the paper leaves open.

HYP, in the authors’ words (Section 1 Introduction (Problem)): “Some (including some reviewers of this paper) argue that any miscompilation bug, whether fuzzer-found or not, is a ticking bomb that should be regarded as severe, or avoided completely via formal verification”

Discourse graph of Do fuzzer-found miscompilation bugs matter for real-world applications? (Proc. ACM Program. Lang., OOPSLA, 2019) que addresses stage1-compile-time-fuzzer-bugs que addresses stage2-binary-differences-fuzzer-bugs que addresses stage3-runtime-divergence-fuzzer-bugs que addresses comparison-alive-and-user-reported-bugs que addresses severity-vs-impact-correlation stage1-compile-time-fuzzer-bugs produces all-27-fuzzer-bugs-reached all-27-fuzzer-bugs-reached supports hyp stage1-compile-time-fuzzer-bugs produces fault-triggering-28-percent fault-triggering-28-percent informs hyp stage2-binary-differences-fuzzer-bugs produces 12-of-27-bugs-change-binaries 12-of-27-bugs-change-binaries informs hyp stage2-binary-differences-fuzzer-bugs produces tiny-fraction-of-functions-affected tiny-fraction-of-functions-affected informs hyp stage3-runtime-divergence-fuzzer-bugs produces single-test-failure-zsh single-test-failure-zsh opposes hyp stage3-runtime-divergence-fuzzer-bugs produces sqlite-test-bed-failure sqlite-test-bed-failure informs hyp stage3-runtime-divergence-fuzzer-bugs produces manual-inspection-low-impact manual-inspection-low-impact informs hyp stage3-runtime-divergence-fuzzer-bugs produces 13-percent-test-runs-crashed 13-percent-test-runs-crashed informs hyp comparison-alive-and-user-reported-bugs produces alive-bugs-trigger-rarely alive-bugs-trigger-rarely informs hyp comparison-alive-and-user-reported-bugs produces user-reported-bugs-not-more-impactful user-reported-bugs-not-more-impactful supports hyp severity-vs-impact-correlation produces severity-poor-predictor-of-impact severity-poor-predictor-of-impact informs hyp stage1-compile-time-fuzzer-bugs informs stage2-binary-differences-fuzzer-bugs: Stage 2 is run on the same builds; the 28% potential-fault rate at Stage 1 falls to 6% of builds with different binaries, which the authors attribute mainly to false alarms from over-approximating fault conditions and in some cases to build particularities (e.g. three packages for Csmith #27392). stage2-binary-differences-fuzzer-bugs informs stage3-runtime-divergence-fuzzer-bugs: Test suites are run only for bug x package pairs whose binaries differ at Stage 2, and the manual inspection samples Stage 2's differing functions. comparison-alive-and-user-reported-bugs comparedWith stage2-binary-differences-fuzzer-bugs: Same methodology and same 309 packages; binary differences for 2/10 user-reported bugs (2% of builds) and 2/8 Alive bugs (7%) against 11/20 bugs and 8% for Csmith and EMI. comparison-alive-and-user-reported-bugs comparedWith stage3-runtime-divergence-fuzzer-bugs: One test failure from the 18 non-fuzzer bugs (leveldb, user-reported #27903) against one from the 27 fuzzer-found bugs (zsh, EMI #29031) plus one in SQLite's test bed (Csmith #13326). severity-vs-impact-correlation extends stage1-compile-time-fuzzer-bugs: Re-aggregates the Stage 1 to 3 data for all 45 bugs (fuzzer-found and non-fuzzer-found) by the severity assigned on the Clang/LLVM bug tracker. ISS · open questions and untried branches this path leaves behind QUE · partial Do miscompilation bugs found by fuzzers in a mature compiler (Clang/LLVM) affect real-world applications, and more or less than bugs found by users or formal verification? Do miscompilation bugs found by fuzzers in a mature compiler (Clang/LLVM) affect real-world applications, and more or less than bugs found by users or formal verification? HYP Fuzzer-found miscompilation bugs in a mature compiler matter: they are severe for real-world applications, and bugs found while compiling real code should matter even more. Fuzzer-found miscompilation bugs in a mature compiler matter: they are severe for real-world applications, and bugs found while compiling real code should matter even more. EXP · partial Stage 1: compile 309 Debian packages (10M lines C/C++) with warning-laden Clang/LLVM for 27 fuzzer-found bugs (10 Csmith, 10 EMI, 5 Orange, 2 Yarpgen)… Stage 1: compile 309 Debian packages (10M lines C/C++) with warning-laden Clang/LLVM for 27 fuzzer-found bugs (10 Csmith, 10 EMI, 5 Orange, 2 Yarpgen); reached, triggered? RES · positive All 27 fuzzer-found bugs had their fixing patch reached by at least one package; the patch was reached in 70% o… All 27 fuzzer-found bugs had their fixing patch reached by at least one package; the patch was reached in 70% of 8284 successful builds and for 19/27 bugs in over 50% of packages. RES · partial 22/27 fuzzer-found bugs and 28% of package builds generated potential faults, falling to 13% where conditions… 22/27 fuzzer-found bugs and 28% of package builds generated potential faults, falling to 13% where conditions were precise; precise conditions were possible for only 19% of bugs. EXP · partial Stage 2: for 27 fuzzer-found bugs, build 309 packages with buggy and fixed compiler, diff binaries bitwise, count assembly functions differing opcode-by-… Stage 2: for 27 fuzzer-found bugs, build 309 packages with buggy and fixed compiler, diff binaries bitwise, count assembly functions differing opcode-by-opcode RES · partial 12/27 fuzzer-found bugs (44%) produced different binaries for at least one package, in 6% of package builds; 7/10… 12/27 fuzzer-found bugs (44%) produced different binaries for at least one package, in 6% of package builds; 7/10 Csmith bugs and 4/10 EMI bugs did so, 1/5 Orange, 0/2 Yarpgen. RES · partial Across all fuzzer bugs 0.2% [6023] of assembly functions differed; 10 of the 12 bugs affect at most 177 functions… Across all fuzzer bugs 0.2% [6023] of assembly functions differed; 10 of the 12 bugs affect at most 177 functions (under 1 per mille); Csmith #27392 peaks at 2.5%, EMI #29031 at 0.3%. EXP · negative-no-effect Stage 3: run each package's Autopkgtest suite on buggy vs fixed binaries where they differ (plus SQLite, 98% coverage suite); manually inspect sampled binary… Stage 3: run each package's Autopkgtest suite on buggy vs fixed binaries where they differ (plus SQLite, 98% coverage suite); manually inspect sampled binary differences RES · negative-no-effect Across all 27 fuzzer-found bugs and 309 packages only a single test failure was observed: zsh compiled with the EMI… Across all 27 fuzzer-found bugs and 309 packages only a single test failure was observed: zsh compiled with the EMI #29031 buggy compiler (test diffs 0 Csmith, 1 EMI, 0 Orange). RES · partial On SQLite (suite covering more than 98% of 151K statements) one failure appeared, Csmith #13326 on test… On SQLite (suite covering more than 98% of 151K statements) one failure appeared, Csmith #13326 on test incrblob-2.0.4, caused by miscompiling the test bed rather than SQLite itself. RES · negative-no-effect Manual inspection of sampled binary differences: for Csmith #11964 all 52 affected functions were reviewed and… Manual inspection of sampled binary differences: for Csmith #11964 all 52 affected functions were reviewed and none can trigger a runtime failure; inspected bugs rated low or very low impact. RES · partial About 13% of the test-suite runs could not be carried out because the testing infrastructure crashed (missing files o… About 13% of the test-suite runs could not be carried out because the testing infrastructure crashed (missing files or dependencies, test infrastructure failing to compile). EXP · positive Same three-stage analysis over the same 309 packages for 18 non-fuzzer bugs (8 from the Alive formal verifier, 10 user- reported from real code), vs the 27… Same three-stage analysis over the same 309 packages for 18 non-fuzzer bugs (8 from the Alive formal verifier, 10 user-reported from real code), vs the 27 fuzzer-found bugs RES · partial Alive bugs: code reached in 43% of builds, 6/8 never trigger (vs 2/20 for Csmith and EMI), yet two Alive bugs… Alive bugs: code reached in 43% of builds, 6/8 never trigger (vs 2/20 for Csmith and EMI), yet two Alive bugs changed binaries in 172 packages and 0.6% [2224] of functions, with 0 test failures. RES · positive User-reported bugs changed binaries for only 2/10 bugs and 2% of builds, vs 11/20 bugs and 8% for Csmith and EMI… User-reported bugs changed binaries for only 2/10 bugs and 2% of builds, vs 11/20 bugs and 8% for Csmith and EMI, with one test failure (leveldb, #27903): fuzzer bugs matter at least as much. EXP · inconclusive-underpowered Re-aggregate impact data for all 45 bugs over 309 packages by bug-tracker severity (8 enhancement, 33 normal, 4 release blocker): does severity predict… Re-aggregate impact data for all 45 bugs over 309 packages by bug-tracker severity (8 enhancement, 33 normal, 4 release blocker): does severity predict impact? RES · inconclusive-underpowered Enhancement-level bugs reached buggy code in 84% of builds vs 55% for normal bugs; release blockers changed binaries… Enhancement-level bugs reached buggy code in 84% of builds vs 55% for normal bugs; release blockers changed binaries in 0.8% of builds vs 3% (enhancement) and 6% (normal); test diffs 0, 2, 0. ISS · next-step Impact on non-functional properties (security, performance) was excluded by assumption; metrics for it, and for the attack surface of bugs used as… Impact on non-functional properties (security, performance) was excluded by assumption; metrics for it, and for the attack surface of bugs used as backdoors, remain to be built. ISS · next-step Test suites are a weak proxy: identical results cannot separate semantic equivalence from weak tests. Symbolic and multi-version execution proposed to… Test suites are a weak proxy: identical results cannot separate semantic equivalence from weak tests. Symbolic and multi-version execution proposed to probe binaries further. ISS · open-question May not generalise beyond mature Clang/LLVM: less mature compilers (e.g. Rust) may have higher-impact bugs; sample is 12% of fixed fuzzer-found… May not generalise beyond mature Clang/LLVM: less mature compilers (e.g. Rust) may have higher-impact bugs; sample is 12% of fixed fuzzer-found miscompilations; replication wanted. ISS · open-question Whether Csmith's higher binary-impact rate than EMI reflects early low-hanging fruit needs more bugs; how to prioritise compiler bug reports better than… Whether Csmith's higher binary-impact rate than EMI reflects early low-hanging fruit needs more bugs; how to prioritise compiler bug reports better than reporter info or intuition.
  • supports positive finding
  • opposes a null, worse or failed result against a control or tuned baseline, with a reported test, interval or variance to show it is real
  • informs bears on the question without deciding the hypothesis
  • thin grey a relation between two experiments
Nodes, in reading order. Sources: Marcozzi, Tang, Donaldson & Cadar 2019, 10.1145/3360581; version of record from the ACM Digital Library, CC BY 4.0, read in full on 19 October 2026.
NodeTextTypeOutcomeEdge
EXPStage 1: compile 309 Debian packages (10M lines C/C++) with warning-laden Clang/LLVM for 27 fuzzer-found bugs (10 Csmith, 10 EMI, 5 Orange, 2 Yarpgen); reached, triggered?
Every fuzzer-found bug's code is reached by at least one package and 22/27 bugs trigger, but fault conditions are precise for only 19% of bugs so the 28% trigger rate is an over-approximation.
measurement study (compile-time reachability and fault triggering)partial
RESAll 27 fuzzer-found bugs had their fixing patch reached by at least one package; the patch was reached in 70% of 8284 successful builds and for 19/27 bugs in over 50% of packages.
fixing patch reached = 5804/8284 builds (70%); bugs reached = 27/27; 19/27 bugs with >50% of packages reaching the patch; Yarpgen #34381 reached for all 307 packages that built; Orange #26407 reached for fewer than 2%
Section 5.1, Table 2, Table 3 · “For each bug, at least one package caused the associated fixing patch to be reached during compilation”
positive
informative
supports HYP
RES22/27 fuzzer-found bugs and 28% of package builds generated potential faults, falling to 13% where conditions were precise; precise conditions were possible for only 19% of bugs.
triggered = 2283/8284 builds (28%); bugs triggered = 22/27 (only 1 with precise conditions); 13% of builds when restricted to precise patches; 39% of builds where the patch is reached trigger; Csmith 34% and EMI 31% of builds triggered, Orange 2%, Yarpgen 42%
Section 5.1 (Fault Triggering), Table 2, Table 3 · “In total, 22/27 compiler bugs and 28% of the package builds generated potential faults. This last number falls to 13%”
partial
informative
informs HYP
EXPStage 2: for 27 fuzzer-found bugs, build 309 packages with buggy and fixed compiler, diff binaries bitwise, count assembly functions differing opcode-by-opcode
Almost half of the fuzzer-found bugs change the binaries of at least one package, but the changes touch a tiny fraction of the generated functions.
measurement study (syntactic binary comparison)partial
RES12/27 fuzzer-found bugs (44%) produced different binaries for at least one package, in 6% of package builds; 7/10 Csmith bugs and 4/10 EMI bugs did so, 1/5 Orange, 0/2 Yarpgen.
packages with binary differences = 477/8284 builds (6%); bugs = 12/27 (44%); Csmith 318 packages (10%) and 7/10 bugs; EMI 151 (5%) and 4/10 bugs; Orange 8 (1%) and 1/5; Yarpgen 0/2; Csmith #27392 and EMI #29031 account for 53% of the builds with differences
Section 5.2, Table 2, Table 3 · “In total, 12/27 fuzzer-found bugs (44%) lead to differences in the generated monolithic binaries for at least one package.”
partial
informative
informs HYP
RESAcross all fuzzer bugs 0.2% [6023] of assembly functions differed; 10 of the 12 bugs affect at most 177 functions (under 1 per mille); Csmith #27392 peaks at 2.5%, EMI #29031 at 0.3%.
functions with syntactic differences = 0.2% [6023] over all fuzzer bugs; 10/12 bugs affect at most 177 functions, less than 1 permille; #27392 2.5% [4997]; #29031 0.3% [639]; percentages relative to an average of around 202K functions (standard deviation 5%) counted for three compiler versions; packages mod-gearman, phyml and Samba excluded
Section 5.2, Table 2 · “10 affect only very few (at most 177) of all the assembly functions generated when compiling our list of packages”
partial
informative
informs HYP
EXPStage 3: run each package's Autopkgtest suite on buggy vs fixed binaries where they differ (plus SQLite, 98% coverage suite); manually inspect sampled binary differences
Only one test failure across all fuzzer bugs and 309 packages (zsh), one more in SQLite's test bed, and manual inspection rates every inspected bug's impact as low or very low.
measurement study (differential test-suite runs and manual inspection)negative-no-effect
RESAcross all 27 fuzzer-found bugs and 309 packages only a single test failure was observed: zsh compiled with the EMI #29031 buggy compiler (test diffs 0 Csmith, 1 EMI, 0 Orange).
test diffs = 1 (zsh, EMI #29031, test case ${(g)...} in D04Parameter04.ztst) out of all bug x package pairs with differing binaries; aggregate test diffs < 0.1% of builds; test suites of 39 measurable packages reach median 47%, mean 46% statement coverage (range 2% to 95%); divergent runs repeated several times in fresh environments
Section 5.3 (Differences in Test Results), Table 2, Appendix A.1 · “Across all bugs and packages, we have only observed a single test failure: when compiling the zsh package”
negative-no-effect
informative
opposes HYP
RESOn SQLite (suite covering more than 98% of 151K statements) one failure appeared, Csmith #13326 on test incrblob-2.0.4, caused by miscompiling the test bed rather than SQLite itself.
SQLite: 1 failing test (incrblob-2.0.4) for Csmith #13326; test coverage more than 98% of 151K statements; same test also fails for the compilers of bugs #11964, #11977, #12189 and #12885, which fall within the lifespan of #13326; no other test differences
Section 5.3 (Additional Experiments), Appendix A.1 · “the miscompilation responsible for this failure does not affect the SQLite code itself, but the code of the test bed responsible for conducting test incrblob-2.0.4”
partial
informative
informs HYP
RESManual inspection of sampled binary differences: for Csmith #11964 all 52 affected functions were reviewed and none can trigger a runtime failure; inspected bugs rated low or very low impact.
#11964: 52 functions in 2 packages (s3ql, simplejson), 0 runtime failures possible, rated low; #27392: a dozen differences inspected, 0 divergences, rated very low; #26323 very low; #29031 low; #30935: 3 differences inspected, 0 divergences, rated low
Section 5.3 (Manual Inspection), Table 2 (manual column), Appendix A.2 · “bug #11964 affects only 52 functions and after manually analysing all of them, we think none can trigger a runtime failure”
negative-no-effect
informative
informs HYP
RESAbout 13% of the test-suite runs could not be carried out because the testing infrastructure crashed (missing files or dependencies, test infrastructure failing to compile).
test-suite runs not carried out = about 13%; fewer than 1% of package builds failed; build failures concentrated in 17 packages, Velvet failing in 52% of builds
Section 5.3 (Failed Test Suite Runs), Section 5.1 (Package Build Failures) · “About 13% of the test suite runs could not be carried out because the underlying testing infrastructure was not reliable and crashed.”
partial
informative
informs HYP
EXPSame three-stage analysis over the same 309 packages for 18 non-fuzzer bugs (8 from the Alive formal verifier, 10 user-reported from real code), vs the 27 fuzzer-found bugs
User-reported and Alive bugs trigger less often and change fewer binaries than Csmith and EMI bugs, with one test failure (leveldb), so fuzzer-found bugs have at least as much impact as bugs from other sources.
benchmark comparison (bug source: fuzzer vs formal verification vs user-reported)positive
RESAlive bugs: code reached in 43% of builds, 6/8 never trigger (vs 2/20 for Csmith and EMI), yet two Alive bugs changed binaries in 172 packages and 0.6% [2224] of functions, with 0 test failures.
Alive (8 bugs): reached 1059/2472 builds (43%), triggered 327 (13%), bugs reached 7/8, bugs triggered 2/8, binary diffs 172 packages (7%) from 2 bugs (#20189 1% [2094], #21242 0% [130]), functions 0.6% [2224], test diffs 0
Section 5.4 (Alive Bugs), Table 4, Table 5 · “6/8 Alive bugs never trigger, compared to only 2/20 for Csmith and EMI”
partial
informative
informs HYP
RESUser-reported bugs changed binaries for only 2/10 bugs and 2% of builds, vs 11/20 bugs and 8% for Csmith and EMI, with one test failure (leveldb, #27903): fuzzer bugs matter at least as much.
User-reported (10 bugs): reached 1990/3070 builds (65%), triggered 593 (19%), bugs reached 8/10, triggered 4/10, binary diffs 56 packages (2%) from 2/10 bugs (#27903 < 0.1% [169], #33706 < 0.1% [9]), functions < 0.1% [178], test diffs 1 (leveldb, #27903); comparison: Csmith+EMI 11/20 bugs and 8% of builds with binary diffs; no SQLite test failure
Section 5.4 (User-reported Bugs), Section 5.6, Table 4, Table 5 · “different binaries are only spotted for 2/10 bugs and 2% of the package builds, far below the values of 11/20 and 8%”
positive
informative
supports HYP
EXPRe-aggregate impact data for all 45 bugs over 309 packages by bug-tracker severity (8 enhancement, 33 normal, 4 release blocker): does severity predict impact?
No clear trend between severity and impact, with some counter-intuitive reversals; the authors note larger samples at the enhancement and release-blocker levels would be needed.
correlation analysis (secondary, same data)inconclusive-underpowered
RESEnhancement-level bugs reached buggy code in 84% of builds vs 55% for normal bugs; release blockers changed binaries in 0.8% of builds vs 3% (enhancement) and 6% (normal); test diffs 0, 2, 0.
enhancement (8 bugs): reached 84%, triggered 40%, binary diffs 3% [279 functions, < 0.1%], test diffs 0; normal (33): reached 55%, triggered 19%, binary diffs 6% [8130, 0.3%], test diffs 2; release blocker (4): reached 97%, triggered 24%, binary diffs 0.8% [16, < 0.1%], test diffs 0; no statistical test reported
Section 5.5, Table 6 · “no clear trend emerged in practice and some numbers are even counter-intuitive”
inconclusive-underpowered
informative
informs HYP
  • ISS Impact on non-functional properties (security, performance) was excluded by assumption; metrics for it, and for the attack surface of bugs used as backdoors, remain to be built. (next-step · Section 7 Future Work (second direction); Section 1 footnote 2)
  • ISS Test suites are a weak proxy: identical results cannot separate semantic equivalence from weak tests. Symbolic and multi-version execution proposed to probe binaries further. (next-step · Section 3.3, Section 6 (Threats to Internal Validity), Section 7 (third direction))
  • ISS May not generalise beyond mature Clang/LLVM: less mature compilers (e.g. Rust) may have higher-impact bugs; sample is 12% of fixed fuzzer-found miscompilations; replication wanted. (open-question · Section 6 (Threats to External Validity), Section 7 (first direction))
  • ISS Whether Csmith's higher binary-impact rate than EMI reflects early low-hanging fruit needs more bugs; how to prioritise compiler bug reports better than reporter info or intuition. (open-question · Section 5.2, Section 5.6)

Extraction notes: VERSION: the text is the version of record (Proc. ACM Program. Lang. 3, OOPSLA, Article 155, October 2019, CC BY 4.0), with PDF extraction artefacts: section signs rendered as 'ğ', quotation marks as 'ł'/'ž', dashes as 'Ð', tables flattened to one row per line (still readable), and one appendix formula garbled ('c1 /nequalc2'). HYPOTHESIS IS IMPLICIT: the paper does not state a hypothesis of its own; the authors say they 'approached this study with an open mind'. The hypothesis label here is my reading of the community claim the paper examines (the 'ticking bomb' quote) combined with the authors' stated prior intuition in Section 5.6 that bugs found while compiling real code 'might trigger more often over applications in the wild than bugs discovered while compiling artificial code', which the results contradicted ('counter-intuitive', 'unexpected result'). The paper's own two conclusions are that (a) miscompilation bugs in a mature compiler seldom impact deployed applications and (b) fuzzer-found bugs have at least as much impact as bugs from other sources; so the headline outcome splits: part (a) opposes 'fuzzer bugs matter', part (b) supports 'fuzzer bugs matter at least as much as user-reported ones'. I set the question outcomeClass to 'partial' for that reason. VALENCE CHOICES THAT ARE MY READING: (1) 'single-test-failure-zsh' is classed negative-no-effect / opposes although there is no statistical test; the paper reports sensitivity checks instead (median 47% statement coverage on the 39 packages gcov could measure, SQLite at more than 98%, divergent runs repeated in fresh environments) and the authors themselves say coverage is 'high enough for not attributing the absence of test suite failures to very poor test coverage', while also calling test suites 'clearly a weak proxy'. A stricter reading would make it inconclusive / consistent-with. (2) 'severity-poor-predictor-of-impact' is classed inconclusive-underpowered because the authors say confidence 'would be increased by bigger samples at the enhancement and release blocker levels' (8 and 4 bugs). (3) The Alive and user-reported comparisons rest on 8 and 10 bugs with no significance test; the paper itself says the Csmith-vs-EMI trend 'should be confirmed using a larger number of bugs'. COUNTS: bugs studied = 45 total: 27 fuzzer-found (10 Csmith, 10 EMI, 5 Orange, 2 Yarpgen), 8 Alive, 10 user-reported. Table 1 lists 35 tool-reported bugs (27 fuzzer + 8 Alive) from 1,033 listed bugs of which 234 were fixed miscompilations; 799 were discarded as unfixed or not miscompilations. The '12%' figure for the fuzzer sample is the paper's own statement; I did not derive it. Packages = 309 (8,283,744 lines C, 782,703 lines C++, 1,250,948 header lines; the paper rounds to 'more than 10 million'). Machine time about 5 months. TABLE ODDITIES: Table 4 shows '0% [130]' for Alive #21242 and Table 2 shows '0% [14]' for Orange #15959, i.e. 0% with a nonzero function count, presumably rounding; the paper does not comment. Function percentages are relative to an approximate average of 202K functions (SD 5%) counted for three compiler versions, as stated in Section 5.2. The abstract counts 'two failures' for fuzzer-found bugs (zsh plus SQLite's test bed) while Table 2 counts 1 because SQLite was an additional experiment outside the 309 packages. Section 5.2 mentions one bug x package pair where the build failed with the buggy compiler because the build ran the test suite; the text says this is detailed 'in the next section' but does not name the package, so I have not attached it to zsh. NOT STATED: no confidence intervals or variance for any rate; the paper gives no per-bug list of which 'manual' inspections were performed beyond the Table 2/4 'manual' column (low / very low / '-').

ChatGPT code-generation non-determinism (ACM TOSEM, 2025)

Software engineering · ACM Trans. Softw. Eng. Methodol. 34(2), 2025

A negative result for a working assumption: one request is not representative, and temperature zero does not make it so.

Read left to right. The question (QUE) is addressed by 5 experiments (EXP), each producing results (RES), and each result bears on the hypothesis (HYP). 0 support it, 5 oppose it, 5 inform it. Issues (ISS) hang below: what the paper leaves open.

HYP, in the authors’ words (Section 4.2 (RQ2); also Section 1 and Abstract): “many people's belief that setting the temperature to 0 can make ChatGPT deterministic [7,13,39], because when setting the temperature to 0, the model applies greedy sampling which should indicate full determinism”

Discourse graph of ChatGPT code-generation non-determinism (ACM TOSEM, 2025) que addresses rq1-default-setting-similarity que addresses rq2-temperature que addresses rq3-one-request-vs-five que addresses rq5-gpt4-vs-gpt35 que addresses literature-survey-nondeterminism-handling rq1-default-setting-similarity produces rq1-zero-equal-output-ratio rq1-zero-equal-output-ratio opposes hyp rq1-default-setting-similarity produces rq1-pass-rate-max-diff rq1-pass-rate-max-diff opposes hyp rq1-default-setting-similarity produces rq1-syntactic-lcs rq1-syntactic-lcs opposes hyp rq1-default-setting-similarity produces rq1-structural-ast rq1-structural-ast informs hyp rq1-default-setting-similarity produces rq1-five-requests-best-vs-worst rq1-five-requests-best-vs-worst informs hyp rq2-temperature produces rq2-temperature-zero-not-deterministic rq2-temperature-zero-not-deterministic opposes hyp rq2-temperature produces rq2-temperature-zero-more-stable-same-pass-rate rq2-temperature-zero-more-stable-same-pass-rate informs hyp rq3-one-request-vs-five produces rq3-single-request-t0-near-identical rq3-single-request-t0-near-identical informs hyp rq5-gpt4-vs-gpt35 produces rq5-gpt4-still-nondeterministic rq5-gpt4-still-nondeterministic opposes hyp literature-survey-nondeterminism-handling produces survey-21-percent-consider survey-21-percent-consider informs hyp rq2-temperature extends rq1-default-setting-similarity: Repeats the RQ1 measurement at temperature 0 and 0.5 on CodeContests; the temperature-1 row of Table 5 is the CodeContests column of Tables 2-4. rq3-one-request-vs-five comparedWith rq2-temperature: The R2 (t=0) row of Table 6 is the temperature-0 row of Table 5; R1 changes only the request configuration (n=5 in one call). rq5-gpt4-vs-gpt35 extends rq2-temperature: Checks whether temperature 0 helps GPT-4 as it helped GPT-3.5; for GPT-4 the two temperatures give near-identical numbers. literature-survey-nondeterminism-handling informs rq1-default-setting-similarity: Shows the practice the RQ1 measurement threatens: most papers evaluate from single requests without controlling for the variance RQ1 measures. ISS · open questions and untried branches this path leaves behind QUE · refuted How non-deterministic is ChatGPT code generation across identical requests, and does setting temperature to 0 remove the non-determinism? How non-deterministic is ChatGPT code generation across identical requests, and does setting temperature to 0 remove the non-determinism? HYP ChatGPT code generation is stable enough that one request is representative, and setting temperature to 0 makes it deterministic (the widely held belief the study tests). ChatGPT code generation is stable enough that one request is representative, and setting temperature to 0 makes it deterministic (the widely held belief the study tests). EXP · refuted RQ1: 829 problems (CodeContests 165, APPS 500, HumanEval 164), 5 requests each to gpt-3.5-turbo-0125 at temperature 1; semantic, syntactic and… RQ1: 829 problems (CodeContests 165, APPS 500, HumanEval 164), 5 requests each to gpt-3.5-turbo-0125 at temperature 1; semantic, syntactic and structural similarity of the candidates RES · refuted Share of tasks with zero equal test outputs across the five candidates (OER = 0) was 75.76% (CodeContests), 51.00%… Share of tasks with zero equal test outputs across the five candidates (OER = 0) was 75.76% (CodeContests), 51.00% (APPS) and 47.56% (HumanEval) at temperature 1. RES · refuted Maximum difference in test pass rate reached 1.00 on all three datasets and occurred in 39.63% of HumanEval… Maximum difference in test pass rate reached 1.00 on all three datasets and occurred in 39.63% of HumanEval problems; Kruskal-Wallis p < 0.05 in 92.1%, 39.4% and 40% of tasks. RES · refuted Mean syntactic similarity (longest common subsequence, LCS) between candidates was only 0.22, 0.23 and 0.42… Mean syntactic similarity (longest common subsequence, LCS) between candidates was only 0.22, 0.23 and 0.42 for CodeContests, APPS and HumanEval; mean Levenshtein edit distance 58.80, 47.37, 26.56. RES · partial Structural (AST) similarity was higher than syntactic: mean United_Diff 0.33, 0.43, 0.60 and Tree_Diff 0.41, 0.54… Structural (AST) similarity was higher than syntactic: mean United_Diff 0.33, 0.43, 0.60 and Tree_Diff 0.41, 0.54, 0.62 for CodeContests, APPS, HumanEval; the authors call this 'high'. RES · positive Across the five requests at temperature 1, the best candidate's pass rate exceeded the worst by about 16.13x… Across the five requests at temperature 1, the best candidate's pass rate exceeded the worst by about 16.13x (CodeContests), 3.12x (APPS) and 1.98x (HumanEval) on average. EXP · refuted RQ2: the 165 CodeContests problems, 5 requests each at temperature 0, 0.5 and 1 (gpt-3.5-turbo-0125); APPS and HumanEval temperature-0 ratios quoted i… RQ2: the 165 CodeContests problems, 5 requests each at temperature 0, 0.5 and 1 (gpt-3.5-turbo-0125); APPS and HumanEval temperature-0 ratios quoted in text only RES · refuted At temperature 0, 43.64% (CodeContests), 27.40% (APPS) and 18.29% (HumanEval) of tasks still had zero equal test outputs… At temperature 0, 43.64% (CodeContests), 27.40% (APPS) and 18.29% (HumanEval) of tasks still had zero equal test outputs across five requests, versus 75.76% at temperature 1 on CodeContests. RES · partial Temperature 0 raised mean LCS from 0.22 to 0.61 and cut mean LED from 58.80 to 23.45 on CodeContests, while mean test… Temperature 0 raised mean LCS from 0.22 to 0.61 and cut mean LED from 58.80 to 23.45 on CodeContests, while mean test pass rate stayed similar (0.15 vs 0.16). EXP · partial RQ3: 165 CodeContests problems; top-5 candidates from one request (n=5, 'R1') versus top-1 candidates from five separate requests ('R2'), at temperatur… RQ3: 165 CodeContests problems; top-5 candidates from one request (n=5, 'R1') versus top-1 candidates from five separate requests ('R2'), at temperature 1 and 0 RES · partial Five candidates from a single request at temperature 0 were almost identical (OER 1.00, zero-equal-output ratio 1.20%, LC… Five candidates from a single request at temperature 0 were almost identical (OER 1.00, zero-equal-output ratio 1.20%, LCS 1.00), unlike five separate requests (OER 0.37, 43.64%). EXP · refuted RQ5: 165 CodeContests problems; gpt-4-0613 versus gpt-3.5-turbo-0125 at temperature 1 and 0, 5 requests each, same measures as RQ1 RQ5: 165 CodeContests problems; gpt-4-0613 versus gpt-3.5-turbo-0125 at temperature 1 and 0, 5 requests each, same measures as RQ1 RES · refuted GPT-4 had zero equal test outputs in 46.06% of CodeContests tasks at temperature 1 (GPT-3.5: 75.76%) and… GPT-4 had zero equal test outputs in 46.06% of CodeContests tasks at temperature 1 (GPT-3.5: 75.76%) and still 41.21% at temperature 0 (GPT-3.5: 43.64%). EXP · positive Survey of 76 LLM code-generation papers (Google Scholar, January 2022 to July 2023, 76 kept from 107 hits) classified by whether they mention or handle non-… Survey of 76 LLM code-generation papers (Google Scholar, January 2022 to July 2023, 76 kept from 107 hits) classified by whether they mention or handle non-determinism RES · positive Only 21.1% (16/76) of surveyed papers considered non-determinism in their experiments (fixed seeds, repeated runs… Only 21.1% (16/76) of surveyed papers considered non-determinism in their experiments (fixed seeds, repeated runs, error bars); 35.5% (27/76) mention it at all. ISS · open-question Why temperature 0 is still non- deterministic is unresolved; the hypotheses named are floating point, unreliable GPU calculation and a sparse… Why temperature 0 is still non-deterministic is unresolved; the hypotheses named are floating point, unreliable GPU calculation and a sparse mixture-of-experts architecture. ISS · untried Only Python was studied; whether other programming languages change the degree of non-determinism is untested. Only Python was studied; whether other programming languages change the degree of non-determinism is untested. ISS · untried Only ChatGPT (GPT-3.5, GPT-4) was studied; the authors say the findings may not apply to other LLMs. Only ChatGPT (GPT-3.5, GPT-4) was studied; the authors say the findings may not apply to other LLMs. ISS · next-step Semantic similarity via test outputs may oversimplify code meaning; embedding- based measures (CodeBERT, GraphCodeBERT) untried; voting and LLM repair loops… Semantic similarity via test outputs may oversimplify code meaning; embedding-based measures (CodeBERT, GraphCodeBERT) untried; voting and LLM repair loops proposed as mitigations.
  • supports positive finding
  • opposes a null, worse or failed result against a control or tuned baseline, with a reported test, interval or variance to show it is real
  • informs bears on the question without deciding the hypothesis
  • thin grey a relation between two experiments
Nodes, in reading order. Sources: Ouyang, Zhang, Harman & Wang 2025, 10.1145/3697010; version of record from the ACM Digital Library, CC BY 4.0, read in full on 19 October 2026.
NodeTextTypeOutcomeEdge
EXPRQ1: 829 problems (CodeContests 165, APPS 500, HumanEval 164), 5 requests each to gpt-3.5-turbo-0125 at temperature 1; semantic, syntactic and structural similarity of the candidates
Code generated from identical prompts differed in test outputs, text and AST for most tasks under the default setting.
measurement study / repeated-request variancerefuted
RESShare of tasks with zero equal test outputs across the five candidates (OER = 0) was 75.76% (CodeContests), 51.00% (APPS) and 47.56% (HumanEval) at temperature 1.
Ratio of worst cases, OER = 0: 75.76% / 51.00% / 47.56% for CodeContests (n=165) / APPS (n=500) / HumanEval (n=164); 5 requests per task; temperature = 1; OER (no ex.) worst cases 81.21% / 53.40% / 51.22%; mean OER 0.09 / 0.27 / 0.39
Section 4.1.1, Table 2, Figure 3 · “the ratios of tasks with zero equal test output (i.e., OER = 0) among the five code candidates are 75.76%, 51.00% and 47.56%”
refuted
informative
opposes HYP
RESMaximum difference in test pass rate reached 1.00 on all three datasets and occurred in 39.63% of HumanEval problems; Kruskal-Wallis p < 0.05 in 92.1%, 39.4% and 40% of tasks.
Max diff of test pass rate = 1.00 (all datasets); ratio of worst cases (max diff = 1) 3.64% / 10.40% / 39.63%; mean variance 0.03 / 0.04 / 0.09; mean test pass rate 0.16 / 0.42 / 0.63; Kruskal-Wallis p < 0.05 in 92.1% of CodeContests, 39.4% of APPS, 40% of HumanEval tasks
Section 4.1.1, Table 2, Figure 2 · “the max diff of the test pass rate reaches 1.00 for all three datasets and accounts for 39.63% of the problems in HumanEval”
refuted
informative
opposes HYP
RESMean syntactic similarity (longest common subsequence, LCS) between candidates was only 0.22, 0.23 and 0.42 for CodeContests, APPS and HumanEval; mean Levenshtein edit distance 58.80, 47.37, 26.56.
LCS mean = 0.22 / 0.23 / 0.42; LCS mean worst = 0.16 / 0.16 / 0.25; LED mean = 58.80 / 47.37 / 26.56 token edits; LED mean worst 77.46 / 61.55 / 43.91; CodeContests / APPS / HumanEval; temperature = 1; 4 comparisons per task against the first candidate plus 20 pairwise
Section 4.1.2, Table 3, Figure 4 · “The mean syntax similarity (LCS) is only 0.22, 0.23 and 0.42 for CodeContests, APPS and HumanEval, respectively.”
refuted
informative
opposes HYP
RESStructural (AST) similarity was higher than syntactic: mean United_Diff 0.33, 0.43, 0.60 and Tree_Diff 0.41, 0.54, 0.62 for CodeContests, APPS, HumanEval; the authors call this 'high'.
United_Diff mean = 0.33 / 0.43 / 0.60, mean worst 0.27 / 0.35 / 0.47, pair mean 0.46 / 0.52 / 0.67; Tree_Diff mean = 0.41 / 0.54 / 0.62, mean worst 0.33 / 0.47 / 0.48, pair mean 0.56 / 0.63 / 0.70; temperature = 1; pycode_similar
Section 4.1.3, Table 4, Figure 5 · “the code candidates generated from the same instruction show great similarity in structure. Specifically, the mean values are 0.33, 0.43 and 0.60”
partial
informative
informs HYP
RESAcross the five requests at temperature 1, the best candidate's pass rate exceeded the worst by about 16.13x (CodeContests), 3.12x (APPS) and 1.98x (HumanEval) on average.
Best-of-5 vs worst-of-5 pass rate improvement: 16.13 times / 3.12 times / 1.98 times; best vs mean of the five: 5.21 / 1.40 / 0.59 times; CodeContests / APPS / HumanEval; temperature = 1; no variance or CI given
Section 7.2 · “shows an improvement on average of around 16.13 times (CodeContests), 3.12 times (APPS) and 1.98 times (HumanEval) over the candidate with the lowest pass rate”
positive
informative
informs HYP
EXPRQ2: the 165 CodeContests problems, 5 requests each at temperature 0, 0.5 and 1 (gpt-3.5-turbo-0125); APPS and HumanEval temperature-0 ratios quoted in text only
Temperature 0 reduced non-determinism on every measure reported but did not remove it.
ablation / hyperparameter sweeprefuted
RESAt temperature 0, 43.64% (CodeContests), 27.40% (APPS) and 18.29% (HumanEval) of tasks still had zero equal test outputs across five requests, versus 75.76% at temperature 1 on CodeContests.
OER ratio of worst cases at temperature 0 = 43.64% / 27.40% / 18.29% (CodeContests n=165 / APPS n=500 / HumanEval n=164); CodeContests at temperature 0.5 = 62.42%, at 1 = 75.76%; OER (no ex.) worst cases at temperature 0 = 54.55% (CodeContests); 5 requests per task; no significance test reported for this comparison
Section 4.2, Table 5 · “there are still 43.64% (CodeContests), 27.40% (APPS) and 18.29% (HumanEval) of problems with no equal test output among the five code candidates”
refuted
informative
opposes HYP
RESTemperature 0 raised mean LCS from 0.22 to 0.61 and cut mean LED from 58.80 to 23.45 on CodeContests, while mean test pass rate stayed similar (0.15 vs 0.16).
CodeContests, temperature 0 / 0.5 / 1: LCS mean 0.61 / 0.33 / 0.22; LED mean 23.45 / 44.48 / 58.80; test pass rate mean 0.15 / 0.16 / 0.16; mean variance 0.01 / 0.02 / 0.03; mean max diff 0.11 / 0.15 / 0.24; United_Diff mean 0.41 / 0.61 / 0.33 (not monotonic); Tree_Diff mean 0.50 / 0.69 / 0.41
Section 4.2, Table 5 · “ChatGPT has better determinism than the default configuration (temperature = 1) for all three types of similarities”
partial
informative
informs HYP
EXPRQ3: 165 CodeContests problems; top-5 candidates from one request (n=5, 'R1') versus top-1 candidates from five separate requests ('R2'), at temperature 1 and 0
Within one request at temperature 0 the five candidates were nearly identical; at temperature 1 both request ways were similarly unstable.
benchmark comparison / request configurationpartial
RESFive candidates from a single request at temperature 0 were almost identical (OER 1.00, zero-equal-output ratio 1.20%, LCS 1.00), unlike five separate requests (OER 0.37, 43.64%).
CodeContests: R1 (t=0) OER mean 1.00, worst-case ratio 1.20%, OER (no ex.) 0.81 / 12.05%, LCS 1.00, LED 0.00, United_Diff 1.00; R2 (t=0) OER 0.37 / 43.64%, LCS 0.61; at temperature 1, R1 OER worst-case ratio 76.09% vs R2 75.76%, LCS 0.21 vs 0.22
Section 4.3, Table 6 · “Code Candidates requested by R1 show higher determinism than those requested by R2.”
partial
informative
informs HYP
EXPRQ5: 165 CodeContests problems; gpt-4-0613 versus gpt-3.5-turbo-0125 at temperature 1 and 0, 5 requests each, same measures as RQ1
GPT-4 was less non-deterministic than GPT-3.5 at temperature 1 but still far from deterministic, and temperature 0 barely changed GPT-4.
benchmark comparison / model comparisonrefuted
RESGPT-4 had zero equal test outputs in 46.06% of CodeContests tasks at temperature 1 (GPT-3.5: 75.76%) and still 41.21% at temperature 0 (GPT-3.5: 43.64%).
OER ratio of worst cases, CodeContests n=165, 5 requests: GPT-4 t=1 46.06%, t=0 41.21%; GPT-3.5 t=1 75.76%, t=0 43.64%; GPT-4 LCS mean 0.61 at both temperatures; test pass rate mean 0.14 (GPT-4) vs 0.16 / 0.15 (GPT-3.5 at t=1 / t=0); GPT-4 United_Diff mean 0.78 at both temperatures
Section 4.5, Table 7 · “GPT-4's non-determinism is pronounced and largely parallels that of GPT-3.5”
refuted
informative
opposes HYP
EXPSurvey of 76 LLM code-generation papers (Google Scholar, January 2022 to July 2023, 76 kept from 107 hits) classified by whether they mention or handle non-determinism
Most surveyed papers neither mention nor control for non-determinism in their experiments.
literature surveypositive
RESOnly 21.1% (16/76) of surveyed papers considered non-determinism in their experiments (fixed seeds, repeated runs, error bars); 35.5% (27/76) mention it at all.
16/76 = 21.1% consider non-determinism in experimental evaluation; 11/76 = 14.5% discuss it without acting on it; 27/76 = 35.5% mention it; 76 papers after excluding posters and vision papers from 107 Google Scholar hits
Section 6.3 (also Section 1) · “Among them, 21.1% (16/76) papers consider non-determinism in their experimental evaluation”
positive
informative
informs HYP
  • ISS Why temperature 0 is still non-deterministic is unresolved; the hypotheses named are floating point, unreliable GPU calculation and a sparse mixture-of-experts architecture. (open-question · Section 4.2)
  • ISS Only Python was studied; whether other programming languages change the degree of non-determinism is untested. (untried · Section 5)
  • ISS Only ChatGPT (GPT-3.5, GPT-4) was studied; the authors say the findings may not apply to other LLMs. (untried · Section 5)
  • ISS Semantic similarity via test outputs may oversimplify code meaning; embedding-based measures (CodeBERT, GraphCodeBERT) untried; voting and LLM repair loops proposed as mitigations. (next-step · Sections 5 and 7.3)

Extraction notes: VERSION: the text is the ACM version of record, ACM Trans. Softw. Eng. Methodol. 34(2), Article 42, publication date January 2025 (received 3 Nov 2023, revised 7 Aug 2024, accepted 23 Aug 2024); the task brief dated it 2024, the paper's own citation line says 2025, so the title uses 2025. The ACM reference line gives 28 pages; CC BY 4.0 licence stated. MODELS: gpt-3.5-turbo-0125 and gpt-4-0613 (Section 3.3). HYPOTHESIS: the paper is a measurement study with no claim of its own; the hypothesis is the belief the paper sets out against (stability and temperature-0 determinism), so findings showing variation are classed 'refuted' / 'opposes'. My reading of the fairness condition: the comparison is against identical-output determinism itself, so no external baseline needed reproducing; the Kruskal-Wallis test with p<0.05 is reported only for RQ1.1 (92.1% / 39.4% / 40% of tasks), not for the temperature-0 or GPT-4 comparisons, which rest on counts of tasks with zero equal outputs out of 165 / 500 / 164 problems with 5 requests each. SAMPLE SIZES: 829 problems in RQ1 (CodeContests 165 = test set, APPS 500 randomly sampled from 5,000, HumanEval 164 = whole set); RQ2, RQ3, RQ5, RQ6 tables are CodeContests only (165), other datasets 'on our homepage'; the APPS 27.40% and HumanEval 18.29% temperature-0 figures appear only in the RQ2 prose, with no table in the paper. Only 5 requests per task; no CI on any ratio. SELF-INCONSISTENCIES: (a) Table 6, R1 (t=0): max diff 0.00 and mean max diff 0.00 but 'ratio of worst cases' 1.20% for test pass rate, which cannot both hold; (b) 1.20% (Table 6 R1) and 1.21% (Table 7 GPT-4) appear for what should be the same 165-problem denominator, unexplained; (c) RQ5 prose says GPT-4 is more deterministic 'with ... lower OER and OER (no ex.), lower LCS, higher LED and lower structural similarity' but Table 7 shows the opposite direction (higher OER 0.35 vs 0.09, higher LCS 0.61 vs 0.22, lower LED); the table direction is the one consistent with 'more deterministic', so I used the table; (d) RQ6 prose gives Concise-prompt mean LCS at t=0 as 0.07 while Table 8 gives 0.70 (I did not use RQ6 as an experiment); (e) RQ2 prose says temperature 0 is more deterministic 'for all three types of similarities', but Table 5 structural mean values are non-monotonic (United_Diff 0.41 at t=0, 0.61 at t=0.5, 0.33 at t=1; Tree_Diff 0.50 / 0.69 / 0.41), only the pair-mean column is highest at t=0; (f) Section 7.2 improvement factors (16.13x etc.) are given without variance or definition of the averaging. OMITTED: RQ4 (correlation of description length and difficulty with similarity, CodeContests heatmap Figure 6, qualitative examples) and RQ6 (Concise vs Chain-of-Thought prompts: at t=0 Concise OER worst-case 41.82%, CoT 46.06%, Base 43.64%; at t=1 no obvious difference) were left out to keep within five experiments; also the EvalPlus robustness check (Section 5, no numbers given) and the shared-error-type analysis (Section 7.2: at least 65.85% / 73.83% / 90.00% share an error type when all fail, at temperature 0). The 'positive' outcomeClass on the literature survey is my reading (a measurement that answered its question), not the authors' wording. The Section 1 phrasing of the survey result is 'only 21.1% of these papers consider the non-determinism threat in their experiments'. Equations in Section 3.4.2 are garbled in the extraction; no numbers were taken from them.

ChatGPT for unit test generation: correctness gaps and the ChatTester refiner (Proc. ACM Softw. Eng. FSE, 2024)

Software engineering · Proc. ACM Softw. Eng. 1, FSE, 2024

A mixed result: generated tests often fail to compile or pass, but the ones that pass resemble human tests; then a method that improves them.

Read left to right. The question (QUE) is addressed by 5 experiments (EXP), each producing results (RES), and each result bears on the hypothesis (HYP). 6 support it, 0 oppose it, 5 inform it. Issues (ISS) hang below: what the paper leaves open.

HYP, in the authors’ words (Abstract): “Our evaluation demonstrates the effectiveness of ChatTester by generating 34.3% more compilable tests and 18.7% more tests with correct assertions than the default ChatGPT.”

Discourse graph of ChatGPT for unit test generation: correctness gaps and the ChatTester refiner (Proc. ACM Softw. Eng. FSE, 2024) que addresses rq1-correctness-1000-focal-methods que addresses rq2-rq4-passing-tests-vs-manual que addresses rq5-chattester-effectiveness-ablation que addresses rq6-generalization-other-llms que addresses rq7-project-level-three-projects rq1-correctness-1000-focal-methods produces chatgpt-pass-rate-24-8 chatgpt-pass-rate-24-8 informs hyp rq1-correctness-1000-focal-methods produces failure-breakdown-symbols-and-assertions failure-breakdown-symbols-and-assertions informs hyp rq1-correctness-1000-focal-methods produces chatgpt-vs-athenatest chatgpt-vs-athenatest supports hyp rq1-correctness-1000-focal-methods produces evosuite-more-correct-than-chatgpt evosuite-more-correct-than-chatgpt informs hyp rq2-rq4-passing-tests-vs-manual produces coverage-near-manual coverage-near-manual supports hyp rq2-rq4-passing-tests-vs-manual produces user-study-readability-usability user-study-readability-usability consistent-with hyp rq5-chattester-effectiveness-ablation produces chattester-headline-gain chattester-headline-gain supports hyp rq5-chattester-effectiveness-ablation produces ablation-both-components-help ablation-both-components-help supports hyp rq5-chattester-effectiveness-ablation produces chattester-time-cost chattester-time-cost informs hyp rq6-generalization-other-llms produces open-source-llm-gains open-source-llm-gains supports hyp rq6-generalization-other-llms produces humaneval-python-check humaneval-python-check supports hyp rq7-project-level-three-projects produces project-coverage-mixed-vs-evosuite project-coverage-mixed-vs-evosuite informs hyp rq1-correctness-1000-focal-methods informs rq5-chattester-effectiveness-ablation: The compilation-error and assertion-error breakdown motivated the two ChatTester components: the iterative compile-fix refiner and the intention prompt (Section 4.5). rq2-rq4-passing-tests-vs-manual informs rq5-chattester-effectiveness-ablation: The finding that passing tests resemble manual ones is the stated reason that improving correctness, rather than quality, is the target of ChatTester. rq5-chattester-effectiveness-ablation extends rq6-generalization-other-llms: Same approach and 100-method set with ChatGPT swapped for two open-source 34B models, and a Python dataset. rq5-chattester-effectiveness-ablation extends rq7-project-level-three-projects: Moves from per-method correctness on held-out pairs to whole-project coverage and a second user study. rq7-project-level-three-projects comparedWith rq1-correctness-1000-focal-methods: Evosuite, far more correct per test in RQ1, is reported as reaching lower coverage than ChatTester on two projects because of unnatural inputs. ISS · open questions and untried branches this path leaves behind QUE · partial How correct, sufficient, readable and usable are ChatGPT-generated Java unit tests, and can ChatGPT itself be used to fix their correctness failures? How correct, sufficient, readable and usable are ChatGPT-generated Java unit tests, and can ChatGPT itself be used to fix their correctness failures? HYP ChatGPT-generated tests fail mostly on compilation and assertions, but passing tests match manual ones; ChatTester (intention prompt + iterative compile- fix loop) raises correctness. ChatGPT-generated tests fail mostly on compilation and assertions, but passing tests match manual ones; ChatTester (intention prompt + iterative compile-fix loop) raises correctness. EXP · partial RQ1: 1,000 Java focal methods from 185 Maven projects; gpt-3.5-turbo basic prompt vs reproduced AthenaTest (CodeT5) and Evosuite; syntactic, compilation… RQ1: 1,000 Java focal methods from 185 Maven projects; gpt-3.5-turbo basic prompt vs reproduced AthenaTest (CodeT5) and Evosuite; syntactic, compilation, execution correctness RES · partial Of 1,000 ChatGPT-generated tests, about 100% are syntactically correct, 42.1% compile and only 24.8% pass execution… Of 1,000 ChatGPT-generated tests, about 100% are syntactically correct, 42.1% compile and only 24.8% pass execution; none of the failures revealed real bugs. RES · partial 579 uncompilable tests are dominated by symbol-resolution errors (cannot find symbol class 1,934 times); 85.5% of… 579 uncompilable tests are dominated by symbol-resolution errors (cannot find symbol class 1,934 times); 85.5% of execution failures are assertion errors, all from incorrect assertions. RES · positive ChatGPT outperforms the reproduced AthenaTest baseline on all three correctness metrics: 42.1% vs 18.8%… ChatGPT outperforms the reproduced AthenaTest baseline on all three correctness metrics: 42.1% vs 18.8% compile and 24.8% vs 14.4% pass; AthenaTest is only 54.8% syntactically correct. RES · inconclusive Evosuite compiles 97.6% and passes 91.4% of its tests versus 42.1% and 24.8% for ChatGPT, but the authors decline to… Evosuite compiles 97.6% and passes 91.4% of its tests versus 42.1% and 24.8% for ChatGPT, but the authors decline to conclude Evosuite is better because it filters tests during search. EXP · positive RQ2-RQ4: coverage (Jacoco) of passing tests vs AthenaTest, Evosuite and the projects' manual tests, plus a blinded user study of 248 passing ChatGPT tests… RQ2-RQ4: coverage (Jacoco) of passing tests vs AthenaTest, Evosuite and the projects' manual tests, plus a blinded user study of 248 passing ChatGPT tests by five developers RES · positive Passing ChatGPT tests reach 82.3% statement and 65.6% branch coverage vs 84.2% and 68.9% for manual tests, above… Passing ChatGPT tests reach 82.3% statement and 65.6% branch coverage vs 84.2% and 68.9% for manual tests, above AthenaTest (65.5/56.2) and Evosuite average (56.9/45.8). RES · positive Five participants (4-5 years Java) scoring 248 passing tests blind on 2-6 scales rated ChatGPT tests comparably… Five participants (4-5 years Java) scoring 248 passing tests blind on 2-6 scales rated ChatGPT tests comparably readable and usable to manual tests; results shown only as stacked bars. EXP · positive RQ5: ChatTester vs default ChatGPT and two ablations (without refiner, without intention generator) on 100 held-out focal methods, three repeated runs… RQ5: ChatTester vs default ChatGPT and two ablations (without refiner, without intention generator) on 100 held-out focal methods, three repeated runs averaged RES · positive ChatTester compiles 73.3% and passes 41.0% of tests vs 39.0% and 22.3% for default ChatGPT, i.e. 34.3% more… ChatTester compiles 73.3% and passes 41.0% of tests vs 39.0% and 22.3% for default ChatGPT, i.e. 34.3% more compilable and 18.7% more passing tests. RES · positive Ablations: the intention generator alone gives 50.7%/29.7% (compile/pass), the refiner alone 60.6%/34.0%; removing the… Ablations: the intention generator alone gives 50.7%/29.7% (compile/pass), the refiner alone 60.6%/34.0%; removing the generator from ChatTester drops 12.7% compile and 7.0% pass. RES · partial ChatTester costs about 99.0 s per test on average (15.0 s for the initial generator, 30.0 s per refinement… ChatTester costs about 99.0 s per test on average (15.0 s for the initial generator, 30.0 s per refinement iteration), dominated by ChatGPT API latency of about 10 s and compilation. EXP · positive RQ6 and Section 7: ChatTester with CodeLlama-Instruct-34B and CodeFuse-34B in place of ChatGPT on the 100-method set, plus a Python check on 164… RQ6 and Section 7: ChatTester with CodeLlama-Instruct-34B and CodeFuse-34B in place of ChatGPT on the 100-method set, plus a Python check on 164 HumanEval methods RES · positive With ChatTester, CodeLlama-34B compilation rises 22.0% -> 43.0% and passing 3.0% -> 21.0%; CodeFuse-34B 1.0… With ChatTester, CodeLlama-34B compilation rises 22.0% -> 43.0% and passing 3.0% -> 21.0%; CodeFuse-34B 1.0% -> 24.0% and 0.0% -> 11.0%; time per test rises from 5 s to 105 s and 90 s. RES · positive On 164 Python methods in HumanEval, ChatTester raises the successful execution rate of ChatGPT-generated… On 164 Python methods in HumanEval, ChatTester raises the successful execution rate of ChatGPT-generated tests from 31.7% to 43.2%. EXP · partial RQ7: ChatTester vs AthenaTest, ChatGPT and Evosuite on every method of three Java projects (3,552-6,303 LOC); project coverage plus a user study on 219 tests… RQ7: ChatTester vs AthenaTest, ChatGPT and Evosuite on every method of three Java projects (3,552-6,303 LOC); project coverage plus a user study on 219 tests per technique RES · partial Project-level coverage: ChatTester 35.1/21.5, 15.6/9.2, 41.8/13.4 (SC/BC %) vs EvoSuite 30.5/16.1, 15.2/9.9… Project-level coverage: ChatTester 35.1/21.5, 15.6/9.2, 41.8/13.4 (SC/BC %) vs EvoSuite 30.5/16.1, 15.2/9.9, 45.3/13.3 and ChatGPT 14.4/5.2, 9.4/5.0, 38.6/12.7 on zappos-json, tabula-java, jInstagram. ISS · untried The refiner fixes only compilation errors, not execution failures, because the authors cannot tell whether a failing test or a buggy focal method is… The refiner fixes only compilation errors, not execution failures, because the authors cannot tell whether a failing test or a buggy focal method is at fault. ISS · next-step ChatTester takes about 99 s per test; the authors name locally deployed small LLMs and incremental compilation of the generated test as untried efficiency… ChatTester takes about 99 s per test; the authors name locally deployed small LLMs and incremental compilation of the generated test as untried efficiency improvements. ISS · open-question The empirical study (RQ1-RQ4) was run once, not repeated, because of user- study effort; only gpt-3.5-turbo was studied, GPT-4 was excluded for API rat… The empirical study (RQ1-RQ4) was run once, not repeated, because of user-study effort; only gpt-3.5-turbo was studied, GPT-4 was excluded for API rate limits. ISS · open-question Manual tests may be in ChatGPT's training data; Levenshtein distance to manual tests averages 1,027 (median 609) characters, 5% of ChatTester tests unde… Manual tests may be in ChatGPT's training data; Levenshtein distance to manual tests averages 1,027 (median 609) characters, 5% of ChatTester tests under 200 characters.
  • supports positive finding
  • opposes a null, worse or failed result against a control or tuned baseline, with a reported test, interval or variance to show it is real
  • informs bears on the question without deciding the hypothesis
  • thin grey a relation between two experiments
Nodes, in reading order. Sources: Yuan, Liu, Ding, Wang, Chen, Peng & Lou 2024, 10.1145/3660783; version of record from the ACM Digital Library, CC BY 4.0, read in full on 19 October 2026.
NodeTextTypeOutcomeEdge
EXPRQ1: 1,000 Java focal methods from 185 Maven projects; gpt-3.5-turbo basic prompt vs reproduced AthenaTest (CodeT5) and Evosuite; syntactic, compilation, execution correctness
Only 24.8% of ChatGPT tests pass; ChatGPT beats the learning-based baseline but is far below Evosuite on correctness.
benchmark comparisonpartial
RESOf 1,000 ChatGPT-generated tests, about 100% are syntactically correct, 42.1% compile and only 24.8% pass execution; none of the failures revealed real bugs.
Syntactical correct ≈ 100.0%, Success compilation 42.1%, Passing execution 24.8%; n = 1,000 tests, single run (study not repeated)
Section 4.1, Table 2 · “42.1% of the generated tests are successfully compiled while only 24.8% of the generated tests are executed successfully without any execution errors”
partial
informative
informs HYP
RES579 uncompilable tests are dominated by symbol-resolution errors (cannot find symbol class 1,934 times); 85.5% of execution failures are assertion errors, all from incorrect assertions.
579 uncompilable tests; cannot find symbol class 1,934, method 471, variable 466; private access 75; assertion errors 148 of the execution failures (85.5%); 17.3% of 1,000 tests compile but fail
Section 4.1, Tables 3 and 4; Introduction · “the majority of failed executions (85.5%) are caused by assertion errors”
partial
informative
informs HYP
RESChatGPT outperforms the reproduced AthenaTest baseline on all three correctness metrics: 42.1% vs 18.8% compile and 24.8% vs 14.4% pass; AthenaTest is only 54.8% syntactically correct.
Success compilation 42.1% vs 18.8%; Passing execution 24.8% vs 14.4%; Syntactical correct ≈100.0% vs 54.8%; n = 1,000 tests; AthenaTest reproduced by fine-tuning CodeT5; no variance reported
Section 4.1, Table 2 · “ChatGPT has a substantial improvement over AthenaTest in terms of syntactic correctness, compilation correctness, and executable correctness”
positive
informative
supports HYP
RESEvosuite compiles 97.6% and passes 91.4% of its tests versus 42.1% and 24.8% for ChatGPT, but the authors decline to conclude Evosuite is better because it filters tests during search.
Evosuite: Success compilation 97.6%, Passing execution 91.4%; ChatGPT: 42.1%, 24.8%; n = 1,000 focal methods; Evosuite default settings; single run, no variance or test
Section 4.1, Table 2 · “we do not intend to conclude that Evosuite is better at generating more correct tests”
inconclusive
informative
informs HYP
EXPRQ2-RQ4: coverage (Jacoco) of passing tests vs AthenaTest, Evosuite and the projects' manual tests, plus a blinded user study of 248 passing ChatGPT tests by five developers
Passing ChatGPT tests reach coverage close to manual tests and are rated comparably readable and usable, though the user study reports no numbers.
benchmark comparison and user studypositive
RESPassing ChatGPT tests reach 82.3% statement and 65.6% branch coverage vs 84.2% and 68.9% for manual tests, above AthenaTest (65.5/56.2) and Evosuite average (56.9/45.8).
Statement coverage: ChatGPT 82.3, AthenaTest 65.5, Evosuite first 68.0 / worst 39.7 / best 76.2 / average 56.9 / union 81.1, Manual 84.2; Branch: 65.6, 56.2, 61.2/31.9/62.1/45.8/77.3, 68.9 (%); subset of focal methods where both ChatGPT and Evosuite produced executable tests, size not stated
Section 4.2, Table 5 · “the tests generated ChatGPT achieve the highest coverage compared to existing learning-based and search-based techniques and it also achieve comparable coverage as manually-written tests”
positive
informative
supports HYP
RESFive participants (4-5 years Java) scoring 248 passing tests blind on 2-6 scales rated ChatGPT tests comparably readable and usable to manual tests; results shown only as stacked bars.
n = 248 passing tests, 5 participants, readability and usability each 2-6, 250$ per participant, two weeks, blinded; no numeric summary or statistical test in the text (Figures 5 and 6)
Sections 3.4, 4.3, 4.4; Figures 5 and 6 · “they are also considered with comparable and sometimes even better readability compared to manually-written tests”
positive
informative
consistent-with HYP
EXPRQ5: ChatTester vs default ChatGPT and two ablations (without refiner, without intention generator) on 100 held-out focal methods, three repeated runs averaged
ChatTester raises compilation from 39.0% to 73.3% and passing from 22.3% to 41.0%, with both components contributing, at about 99 s per test.
benchmark comparison with ablationpositive
RESChatTester compiles 73.3% and passes 41.0% of tests vs 39.0% and 22.3% for default ChatGPT, i.e. 34.3% more compilable and 18.7% more passing tests.
Success compilation 39.0% -> 73.3% (+34.3%); Passing execution 22.3% -> 41.0% (+18.7%); Syntactical correct 100.0% both; n = 100 held-out data pairs; average of 3 runs, no variance reported
Section 6.2.1, Table 7 · “additional 34.3% tests (= 73.3% - 39.0%) can be successfully compiled and additional 18.7% tests (= 41.0% - 22.3%) can pass the execution”
positive
informative
supports HYP
RESAblations: the intention generator alone gives 50.7%/29.7% (compile/pass), the refiner alone 60.6%/34.0%; removing the generator from ChatTester drops 12.7% compile and 7.0% pass.
ChatTester-Ite 50.7/29.7, ChatTester-Ini 60.6/34.0, ChatTester 73.3/41.0 (compile/pass, %); 12.5% of incorrect assertions fixed by the initial generator; refiner adds 22.6% compilable and 11.3% passing tests over ChatTester-Ite; n = 100, 3 runs averaged
Section 6.2.1, Table 7 · “removing the initial test generator would decrease 12.7% compilation rate and 7.0% passing rate”
positive
informative
supports HYP
RESChatTester costs about 99.0 s per test on average (15.0 s for the initial generator, 30.0 s per refinement iteration), dominated by ChatGPT API latency of about 10 s and compilation.
Average time cost ≈ 99.0 s per test; initial generator 15.0 s; each refinement iteration 30.0 s; API latency ≈ 10 s; up to 10 iterations observed (Table 8); n = 100
Section 6.2.1, Table 8 · “The average time cost of ChatTester is around 99.0 seconds, where the initial test generator takes 15.0 seconds”
partial
informative
informs HYP
EXPRQ6 and Section 7: ChatTester with CodeLlama-Instruct-34B and CodeFuse-34B in place of ChatGPT on the 100-method set, plus a Python check on 164 HumanEval methods
ChatTester improves compilation and passing rates for both open-source models and for Python, at roughly 20x the time cost of a single prompt.
generalization studypositive
RESWith ChatTester, CodeLlama-34B compilation rises 22.0% -> 43.0% and passing 3.0% -> 21.0%; CodeFuse-34B 1.0% -> 24.0% and 0.0% -> 11.0%; time per test rises from 5 s to 105 s and 90 s.
CodeLlama-34B: syntactic 93.0/93.0, compile 22.0/43.0, pass 3.0/21.0; CodeFuse-34B: syntactic 72.0/89.0, compile 1.0/24.0, pass 0.0/11.0 (default/ChatTester, %); average time 5 s, 105 s, 5 s, 90 s; n = 100; repetitions not stated for RQ6
Section 6.2.2, Table 9 · “ChatTester achieves 21.0%/ 23.0% improvement in compilation rate and 11.0% /18.0% improvement in passing execution rate”
positive
informative
supports HYP
RESOn 164 Python methods in HumanEval, ChatTester raises the successful execution rate of ChatGPT-generated tests from 31.7% to 43.2%.
Successful execution rate 31.7% -> 43.2%; n = 164 Python methods (HumanEval); repetitions and compilation metric not stated
Section 7 (Threats to Validity) · “improving the successful execution rate of ChatGPT-generated tests from 31.7% to 43.2%”
positive
informative
supports HYP
EXPRQ7: ChatTester vs AthenaTest, ChatGPT and Evosuite on every method of three Java projects (3,552-6,303 LOC); project coverage plus a user study on 219 tests per technique
ChatTester beats ChatGPT and AthenaTest on coverage in all three projects but trails Evosuite on two of six coverage cells; user study favours ChatTester without reported numbers.
case studypartial
RESProject-level coverage: ChatTester 35.1/21.5, 15.6/9.2, 41.8/13.4 (SC/BC %) vs EvoSuite 30.5/16.1, 15.2/9.9, 45.3/13.3 and ChatGPT 14.4/5.2, 9.4/5.0, 38.6/12.7 on zappos-json, tabula-java, jInstagram.
Statement/branch coverage (%): zappos-json ChatTester 35.1/21.5, EvoSuite 30.5/16.1, ChatGPT 14.4/5.2, AthenaTest 7.2/1.3; tabula-java 15.6/9.2, 15.2/9.9, 9.4/5.0, 3.2/0.4; jInstagram 41.8/13.4, 45.3/13,3 (sic), 38.6/12.7, 18.9/1.6; one Evosuite test per focal method; repetitions not stated
Section 6.2.3, Table 10 · “ChatTester achieves comparable and even better coverage than the baselines in the project-level evaluation setting”
partial
informative
informs HYP
  • ISS The refiner fixes only compilation errors, not execution failures, because the authors cannot tell whether a failing test or a buggy focal method is at fault. (untried · Section 5.2)
  • ISS ChatTester takes about 99 s per test; the authors name locally deployed small LLMs and incremental compilation of the generated test as untried efficiency improvements. (next-step · Section 6.2.1)
  • ISS The empirical study (RQ1-RQ4) was run once, not repeated, because of user-study effort; only gpt-3.5-turbo was studied, GPT-4 was excluded for API rate limits. (open-question · Sections 3.4 and 7)
  • ISS Manual tests may be in ChatGPT's training data; Levenshtein distance to manual tests averages 1,027 (median 609) characters, 5% of ChatTester tests under 200 characters. (open-question · Section 7)

Extraction notes: Version: the text is the version of record, Proc. ACM Softw. Eng. Vol. 1, No. FSE, Article 76, July 2024, received 2023-09-28, accepted 2024-04-16, CC BY 4.0. Hypothesis choice (my reading): the paper is a two-part study plus method; I used the ChatTester claim from the abstract as the hypothesis and treated RQ1-RQ4 as experiments that inform it rather than test it, so the study findings carry 'informs'. Numbers: 17.3% (compile but fail) comes from the Introduction, not Table 2; 85.5% assertion-error share is the paper's own figure (Table 4 rows sum to 173, which is my addition, not stated). The coverage in Table 5 is computed on the subset of focal methods where both ChatGPT and Evosuite produced executable tests; the subset size is not stated. Table 5: the paper says ChatGPT has the highest coverage among existing techniques, but Evosuite union branch coverage (77.3%) exceeds ChatGPT (65.6%); this holds only against Evosuite first/worst/best/average (my reading). User studies (RQ3, RQ4, RQ7) are reported only as stacked bar charts (Figures 5, 6, 10) with no numeric summaries and no statistical test in the text, so I set their valence to consistent-with rather than supports; the RQ7 user study (219 tests per technique, 0.05 margin at 95% confidence) is mentioned in the RQ7 experiment label but has no finding of its own because no numbers are given. Fairness: the ChatTester vs ChatGPT comparison uses the authors' own baseline run, averaged over 3 runs, but no variance, CI or significance test is reported; AthenaTest is a reproduction by fine-tuning CodeT5 because the original BART model was not released, so 'ChatGPT beats AthenaTest' is against a proxy. Evosuite's higher correctness (97.6%/91.4%) is classed inconclusive because the authors themselves say the comparison does not decide (Evosuite filters invalid tests post-generation while ChatGPT has no validation). Table 8 (iteration distribution) columns sum to 100 tests, 69 compiled and 42 passing, which differs from the Table 7 averages of 73.3% and 41.0%; Table 8 appears to be a single run (my inference, not stated). Table 9 header is garbled in the extraction (model-name subscripts rendered as Unicode math codepoints); I read the columns as CodeLlama-34B default/ChatTester and CodeFuse-34B default/ChatTester, which matches the text's 21.0%/23.0% and 11.0%/18.0% improvements. Table 10 prints EvoSuite jInstagram branch coverage as '13,3', presumably 13.3; I copied it as printed. Self-inconsistency: the RQ7 summary says ChatTester 'consistently outperforms baselines in coverage', but Table 10 shows EvoSuite higher on jInstagram statement coverage (45.3 vs 41.8) and tabula-java branch coverage (9.9 vs 9.2); the body text's 'comparable and even better' is the accurate statement. Whether RQ6 and RQ7 were repeated three times is not explicitly stated (Section 7 says repetition applied 'when automatically evaluating the effectiveness of ChatTester'). The Introduction's phrase 'since the idea of ChatGPT is general and not limited to the specific model' presumably means ChatTester. The HumanEval Python result appears only in Threats to Validity with no table. The abstract's '18.7% more tests with correct assertions' corresponds to the passing-execution rate in Table 7; the paper equates passing with correct assertions. Assertion-count distribution (Figure 4) is described only qualitatively and is omitted.

Community Notes roll-out and engagement with misinformation on X/Twitter (Proc. ACM HCI, CSCW, 2024)

Human-computer interaction · Proc. ACM Hum.-Comput. Interact. 8, CSCW2, 2024

A null result: no evidence that the intervention reduced engagement with misleading posts, with an explanation of why.

Read left to right. The question (QUE) is addressed by 5 experiments (EXP), each producing results (RES), and each result bears on the hypothesis (HYP). 0 support it, 6 oppose it, 6 inform it. Issues (ISS) hang below: what the paper leaves open.

HYP, in the authors’ words (Section 5.1 Research Implications): “From this perspective, misleading tweets with CRH notes are expected to have lower engagement, compared to misleading tweets without CRH notes.”

Discourse graph of Community Notes roll-out and engagement with misinformation on X/Twitter (Proc. ACM HCI, CSCW, 2024) que addresses fact-check-volume-and-delay que addresses did-fcrh-vs-fncrh que addresses placebo-did-tests que addresses rdd-note-display que addresses confounding-and-same-author-checks fact-check-volume-and-delay produces contributors-and-notes-surge contributors-and-notes-surge informs hyp fact-check-volume-and-delay produces note-delay-exceeds-half-life note-delay-exceeds-half-life informs hyp did-fcrh-vs-fncrh produces did-us-rollout-apparent-reduction did-us-rollout-apparent-reduction informs hyp did-fcrh-vs-fncrh produces did-world-rollout-null did-world-rollout-null opposes hyp placebo-did-tests produces placebo-tnmr-same-reduction placebo-tnmr-same-reduction informs hyp placebo-did-tests produces fcrh-vs-tnmr-null fcrh-vs-tnmr-null opposes hyp placebo-did-tests produces short-delay-subgroup-null short-delay-subgroup-null opposes hyp rdd-note-display produces rdd-no-discontinuity rdd-no-discontinuity opposes hyp rdd-note-display produces rdd-delay-no-effect rdd-delay-no-effect informs hyp confounding-and-same-author-checks produces same-author-ocn-null same-author-ocn-null opposes hyp confounding-and-same-author-checks produces engagement-rate-null engagement-rate-null opposes hyp confounding-and-same-author-checks produces global-decline-not-musk-or-contributors global-decline-not-musk-or-contributors informs hyp fact-check-volume-and-delay informs did-fcrh-vs-fncrh: Response-time measurements (display delay 2.2-2.9 days vs 79.5-minute half-life) supply the paper's explanation for why the roll-out produced no measurable reduction. placebo-did-tests contradicts did-fcrh-vs-fncrh: The same U.S.-roll-out drop appears for not-misleading T-NMR tweets vs F-NCRH, and vanishes when F-CRH is compared with T-NMR, so the Table 2 effect is not attributable to displayed notes. fact-check-volume-and-delay informs placebo-did-tests: The shortest display delay (80.2 min) exceeds the half-life, so the short-delay subgroup used the 25th percentile (0.569 day) instead of a half-life cutoff. rdd-note-display confirms placebo-did-tests: Complementary design at the note-display level finds no discontinuity at the 0.40 cutoff, consistent with the null DiD result. confounding-and-same-author-checks extends did-fcrh-vs-fncrh: Adds Musk, contributor-cohort and Month-Year controls, cross-period matching, same-author controls and per-impression rates; the null result persists and the global decline is traced to newly included authors. confounding-and-same-author-checks confirms rdd-note-display: Independent robustness checks reach the same null conclusion as the RDD. ISS · open questions and untried branches this path leaves behind QUE · negative-no-effect Did the roll-out of Community Notes to the U.S. (Oct 6, 2022) and the world (Dec 11, 2022) reduce retweets and likes of misleading tweets on X/Twitter? Did the roll-out of Community Notes to the U.S. (Oct 6, 2022) and the world (Dec 11, 2022) reduce retweets and likes of misleading tweets on X/Twitter? HYP Displaying helpful (CRH) community notes reduces engagement with misleading tweets, so misleading tweets with visible notes should receive fewer retweets and likes than those without. Displaying helpful (CRH) community notes reduces engagement with misleading tweets, so misleading tweets with visible notes should receive fewer retweets and likes than those without. EXP · positive Descriptive analysis of 30,267 English fact-checked tweets (Jul 2021-Apr 2023): contributor growth, notes per tweet, and delay from tweet creation to note… Descriptive analysis of 30,267 English fact-checked tweets (Jul 2021-Apr 2023): contributor growth, notes per tweet, and delay from tweet creation to note creation and display RES · positive 76% of all 64,359 contributors (48,927) joined after the global expansion; notes-to-tweets ratio rose from 1.37… 76% of all 64,359 contributors (48,927) joined after the global expansion; notes-to-tweets ratio rose from 1.37 (Invisible) to 1.62 (Visible US) to 1.79 (Visible World). RES · partial Delay from tweet to note creation fell from 5.21 to 3.08 days (Visible US, t=3.511, p<0.001) to 1.82 days (World… Delay from tweet to note creation fell from 5.21 to 3.08 days (Visible US, t=3.511, p<0.001) to 1.82 days (World, t=7.763, p<0.001); display delay fell only from 2.85 to 2.23 days (t=2.286, p<0.05). EXP · partial DiD, negative binomial: misleading tweets with helpful notes (F-CRH, 3,387) vs misleading tweets without (F-NCRH, 20,669), PSM-matched (38 of 24,056… DiD, negative binomial: misleading tweets with helpful notes (F-CRH, 3,387) vs misleading tweets without (F-NCRH, 20,669), PSM-matched (38 of 24,056 discarded), two interventions RES · partial After the U.S. roll-out, F-CRH tweets got 35.5% fewer retweets (95% CI [-53.1%, -11.4%]; coef. -0.439, p<0.01)… After the U.S. roll-out, F-CRH tweets got 35.5% fewer retweets (95% CI [-53.1%, -11.4%]; coef. -0.439, p<0.01) and 33.2% fewer likes (95% CI [-51.9%, -7.2%]; coef. -0.403, p<0.05), n=5,019. RES · negative-no-effect After the global roll-out, FCRH x Vis was non-significant for retweets (-0.123, SE 0.133) and likes (-0.127, S… After the global roll-out, FCRH x Vis was non-significant for retweets (-0.123, SE 0.133) and likes (-0.127, SE 0.132), n=11,821; both groups fell in parallel (Vis -0.761***, -0.809***). EXP · negative-no-effect Two placebo DiD tests using not- misleading tweets (T-NMR, 5,602): T-NMR vs F-NCRH as virtual treatment, and F-CRH vs T-NMR as control; plus a short… Two placebo DiD tests using not-misleading tweets (T-NMR, 5,602): T-NMR vs F-NCRH as virtual treatment, and F-CRH vs T-NMR as control; plus a short-delay subgroup (<=0.569 day) RES · inconclusive-controls-failed Not-misleading T-NMR tweets also got 39.5% fewer retweets (95% CI [-59.5%, -9.9%]; coef. -0.503, p<0.05) and 35.5%… Not-misleading T-NMR tweets also got 39.5% fewer retweets (95% CI [-59.5%, -9.9%]; coef. -0.503, p<0.05) and 35.5% fewer likes (95% CI [-55.5%, -6.6%]; coef. -0.439, p<0.05) after US roll-out, n=5044. RES · negative-no-effect With T-NMR as control, FCRH x Vis was non-significant in all four columns (-0.184, 0.029, -0.118, -0.022; SEs… With T-NMR as control, FCRH x Vis was non-significant in all four columns (-0.184, 0.029, -0.118, -0.022; SEs 0.176, 0.117, 0.177, 0.123), n=1,716 (Pre-US) and 6,463 (US-World). RES · negative-no-effect Restricting F-CRH to tweets noted within 0.569 day (25th percentile of display delay), FCRH x Vis stayed non-… Restricting F-CRH to tweets noted within 0.569 day (25th percentile of display delay), FCRH x Vis stayed non-significant (-0.009, -0.141, 0.113, -0.261), n=1,293 and 4,823 for retweets. EXP · negative-no-effect RDD at the note helpfulness cutoff 0.40 (window 0.20), post-roll-out tweets only: F-CRH (2,133) vs F-NCRH (9,671), PSM omitted 325 of 5,255; Core model… RDD at the note helpfulness cutoff 0.40 (window 0.20), post-roll-out tweets only: F-CRH (2,133) vs F-NCRH (9,671), PSM omitted 325 of 5,255; Core model v1.0 notes RES · negative-no-effect Treated coefficient non-significant for retweets (0.157, SE 0.121; World 0.114, SE 0.134) and likes (0.180, SE 0.132… Treated coefficient non-significant for retweets (0.157, SE 0.121; World 0.114, SE 0.134) and likes (0.180, SE 0.132; World 0.044, SE 0.147), n=4,930 (Roll-Out) and 3,951 (World). RES · negative-no-association Delay coefficients in the RDD were non- significant (0.018, -0.087, -0.020) or negative (-0.133, p<0.05 for likes… Delay coefficients in the RDD were non-significant (0.018, -0.087, -0.020) or negative (-0.133, p<0.05 for likes, World), so fact-checking speed did not reduce engagement. EXP · negative-no-effect Robustness: Musk acquisition, old-vs-new contributors, Month-Year fixed effects, alternative metrics, cross-period matching, same-author control (OCN… Robustness: Musk acquisition, old-vs-new contributors, Month-Year fixed effects, alternative metrics, cross-period matching, same-author control (OCN, 374,601 tweets), rates RES · negative-no-effect Against the same authors' un-noted tweets (OCN), FCRH x Vis was non- significant: -0.669 (SE 0.422), -0.121… Against the same authors' un-noted tweets (OCN), FCRH x Vis was non-significant: -0.669 (SE 0.422), -0.121 (0.305) retweets; -0.524 (0.429), -0.401 (0.290) likes; n=538 and 1,874. RES · negative-no-association Binomial regression of retweet and like rate (per impression) found FCRH non- significant: -0.014 (SE 0.249) and… Binomial regression of retweet and like rate (per impression) found FCRH non-significant: -0.014 (SE 0.249) and -0.388 (SE 0.256), robust to Month-Year effects, n=612 (306 of 328 F-CRH matched). RES · partial With Musk, OldWriter and Month-Year controls, FCRH x Vis stayed -0.438** and -0.411* (Pre-US) and n.s. (US-World)… With Musk, OldWriter and Month-Year controls, FCRH x Vis stayed -0.438** and -0.411* (Pre-US) and n.s. (US-World); Musk and OldWriter n.s.; Month-Year effects -1.186*** (2023/02), -1.229*** (2023/03). ISS · untried Analysis is limited to English tweets; a multilingual evaluation of Community Notes is needed as the program establishes itself elsewhere. Analysis is limited to English tweets; a multilingual evaluation of Community Notes is needed as the program establishes itself elsewhere. ISS · next-step Only aggregated retweet and like counts were available; per-tweet engagement timelines before and after a note appears remain unexamined. Only aggregated retweet and like counts were available; per-tweet engagement timelines before and after a note appears remain unexamined. ISS · open-question 14% of fact-checked tweets were unavailable via the API (82.6% retrieval for CRH tweets); removed misleading tweets could mean the effect of… 14% of fact-checked tweets were unavailable via the API (82.6% retrieval for CRH tweets); removed misleading tweets could mean the effect of Community Notes is underestimated. ISS · untried A pre-selection mechanism that pushes likely-misleading tweets to contributors early in diffusion is proposed to cut fact-checking delay but not tested. A pre-selection mechanism that pushes likely-misleading tweets to contributors early in diffusion is proposed to cut fact-checking delay but not tested.
  • supports positive finding
  • opposes a null, worse or failed result against a control or tuned baseline, with a reported test, interval or variance to show it is real
  • informs bears on the question without deciding the hypothesis
  • thin grey a relation between two experiments
Nodes, in reading order. Sources: Chuai, Tian, Pröllochs & Lenzini 2024, 10.1145/3686967; version of record from the ACM Digital Library, CC BY 4.0, read in full on 19 October 2026.
NodeTextTypeOutcomeEdge
EXPDescriptive analysis of 30,267 English fact-checked tweets (Jul 2021-Apr 2023): contributor growth, notes per tweet, and delay from tweet creation to note creation and display
Fact-checking volume and speed rose sharply after the roll-outs, but notes still appear days after posting, far beyond a tweet's 79.5-minute impression half-life.
observational measurement with regression on response number and response timepositive
RES76% of all 64,359 contributors (48,927) joined after the global expansion; notes-to-tweets ratio rose from 1.37 (Invisible) to 1.62 (Visible US) to 1.79 (Visible World).
contributors joining after global expansion = 48,927 of 64,359 (76%), 'more than 24-fold increase' vs Visible US phase; notes/tweet ratio 1.37 -> 1.62 -> 1.79; mean 1.58 notes per tweet, 32.2% of tweets with more than one note; Verified coef. 0.781*** (notes) and 0.756*** (ratings), Table 1, n = 30,267
Section 4.1, Fig. 1, Table 1 columns (1)-(2) · “48,927 contributors (76%) joined after the global expansion of Community Notes, marking a more than 24-fold increase”
positive
informative
informs HYP
RESDelay from tweet to note creation fell from 5.21 to 3.08 days (Visible US, t=3.511, p<0.001) to 1.82 days (World, t=7.763, p<0.001); display delay fell only from 2.85 to 2.23 days (t=2.286, p<0.05).
mean tweet-to-note-creation delay = 5.21 days (pre), 3.08 days (Visible US, t = 3.511, p < 0.001), 1.82 days (Visible World, t = 7.763, p < 0.001); mean tweet-to-note-display delay = 2.85 days (Visible US) to 2.23 days (Visible World, t = 2.286, p < 0.05); shortest display delay in dataset = 80.2 minutes vs median tweet half-life of about 79.5 minutes (ref. [51])
Section 4.1, Fig. 2, footnote 6; Section 4.3 'Consideration of the fact-checking delay' · “these response times are significantly longer than the typical half-life of tweets”
partial
informative
informs HYP
EXPDiD, negative binomial: misleading tweets with helpful notes (F-CRH, 3,387) vs misleading tweets without (F-NCRH, 20,669), PSM-matched (38 of 24,056 discarded), two interventions
A significant relative drop in F-CRH engagement after the U.S. roll-out, none after the global roll-out; the placebo test later shows the first drop is not specific to misleading tweets.
quasi-experimental difference-in-differences at the feature roll-out levelpartial
RESAfter the U.S. roll-out, F-CRH tweets got 35.5% fewer retweets (95% CI [-53.1%, -11.4%]; coef. -0.439, p<0.01) and 33.2% fewer likes (95% CI [-51.9%, -7.2%]; coef. -0.403, p<0.05), n=5,019.
FCRH x Vis (Pre-US) = -0.439 (robust SE 0.162, p < 0.01) for retweet count and -0.403 (SE 0.168, p < 0.05) for like count; authors' translation: 35.5% fewer retweets (95% CI [-53.1%, -11.4%]) and 33.2% fewer likes (95% CI [-51.9%, -7.2%]); Observations = 5,019; stable with Musk, OldWriter and Month-Year controls (Table A7: -0.438**, -0.411*)
Section 4.2, Table 2 columns (1) and (3); Table A7 · “F-CRH tweets received 35.5% fewer retweets (95% CI:[-53.1%,-11.4%]) and 33.2% fewer likes (95% CI:[-51.9%,-7.2%])”
partial
informative
informs HYP
RESAfter the global roll-out, FCRH x Vis was non-significant for retweets (-0.123, SE 0.133) and likes (-0.127, SE 0.132), n=11,821; both groups fell in parallel (Vis -0.761***, -0.809***).
FCRH x Vis (US-World) = -0.123 (robust SE 0.133, n.s.) for retweet count and -0.127 (SE 0.132, n.s.) for like count; Vis = -0.761*** and -0.809***; Observations = 11,821; negative binomial regression
Section 4.2, Table 2 columns (2) and (4), Fig. 3 · “the coefficients of FCRH x Vis for both retweet count and like count are found to be statistically non-significant”
negative-no-effect
informative
opposes HYP
EXPTwo placebo DiD tests using not-misleading tweets (T-NMR, 5,602): T-NMR vs F-NCRH as virtual treatment, and F-CRH vs T-NMR as control; plus a short-delay subgroup (<=0.569 day)
The U.S. roll-out 'effect' appears equally for non-misleading tweets, and misleading vs non-misleading tweets show no differential change in either intervention, even for quickly noted tweets.
placebo / falsification test of the DiD designnegative-no-effect
RESNot-misleading T-NMR tweets also got 39.5% fewer retweets (95% CI [-59.5%, -9.9%]; coef. -0.503, p<0.05) and 35.5% fewer likes (95% CI [-55.5%, -6.6%]; coef. -0.439, p<0.05) after US roll-out, n=5044.
TNMR x Vis (Pre-US) = -0.503 (robust SE 0.204, p < 0.05) retweets, -0.439 (SE 0.189, p < 0.05) likes; authors' translation 39.5% fewer retweets (95% CI [-59.5%, -9.9%]), 35.5% fewer likes (95% CI [-55.5%, -6.6%]); Observations = 5,044; US-World: 0.060 (SE 0.112) and 0.078 (SE 0.111), n.s., n = 13,328; PSM discarded 255 of 26,271 (0.97%)
Section 4.3.1, Table A4 · “engagement with tweets in the T-NMR group also decrease even though they have no CRH notes”
inconclusive-controls-failed
informative
informs HYP
RESWith T-NMR as control, FCRH x Vis was non-significant in all four columns (-0.184, 0.029, -0.118, -0.022; SEs 0.176, 0.117, 0.177, 0.123), n=1,716 (Pre-US) and 6,463 (US-World).
FCRH x Vis = -0.184 (SE 0.176) and 0.029 (SE 0.117) for retweet count; -0.118 (SE 0.177) and -0.022 (SE 0.123) for like count; all n.s.; Observations = 1,716 (Pre-US), 6,463 (US-World); PSM discarded 490 of 8,989 (5.5%); parallel trends hold across all periods (Fig. A2(c), Tables A15-A16)
Section 4.3.2, Table 3, Fig. 4 · “we further validate that there is no significant treatment effect for the two interventions”
negative-no-effect
informative
opposes HYP
RESRestricting F-CRH to tweets noted within 0.569 day (25th percentile of display delay), FCRH x Vis stayed non-significant (-0.009, -0.141, 0.113, -0.261), n=1,293 and 4,823 for retweets.
FCRH x Vis = -0.009 (SE 0.216), -0.141 (SE 0.188) retweets; 0.113 (SE 0.215), -0.261 (SE 0.198) likes; all n.s.; Observations reported as 1,293 / 4,823 (retweet columns) and 1,716 / 6,463 (like columns); subgroup = F-CRH tweets with CRH note displayed within 0.569 day; control T-NMR
Section 4.3 'Consideration of the fact-checking delay', Table A5 · “the coefficients of FCRH x Vis in the four columns are all not statistically significant”
negative-no-effect
informative
opposes HYP
EXPRDD at the note helpfulness cutoff 0.40 (window 0.20), post-roll-out tweets only: F-CRH (2,133) vs F-NCRH (9,671), PSM omitted 325 of 5,255; Core model v1.0 notes
No discontinuity in retweets or likes at the display threshold, in the whole roll-out period or the world period; fact-checking delay has no significant effect either.
quasi-experimental regression discontinuity at the note display levelnegative-no-effect
RESTreated coefficient non-significant for retweets (0.157, SE 0.121; World 0.114, SE 0.134) and likes (0.180, SE 0.132; World 0.044, SE 0.147), n=4,930 (Roll-Out) and 3,951 (World).
Treated = 0.157 (robust SE 0.121) retweet count Roll-Out, 0.114 (SE 0.134) World; 0.180 (SE 0.132) like count Roll-Out, 0.044 (SE 0.147) World; all n.s.; Observations = 4,930 and 3,951; negative binomial; cutoff NoteScore 0.40, window width 0.20
Section 4.4, Table 4, Fig. 5 · “The coefficients of Treated in Columns (1) and (3) of Table 4 are not statistically significant”
negative-no-effect
informative
opposes HYP
RESDelay coefficients in the RDD were non-significant (0.018, -0.087, -0.020) or negative (-0.133, p<0.05 for likes, World), so fact-checking speed did not reduce engagement.
Delay = 0.018 (SE 0.033), -0.087 (SE 0.053), -0.020 (SE 0.035), -0.133* (SE 0.053, p < 0.05); Table 4 columns (1)-(4)
Section 4.4, Table 4 · “the coefficients of Delay in Table 4 are not significant or even negative”
negative-no-association
informative
informs HYP
EXPRobustness: Musk acquisition, old-vs-new contributors, Month-Year fixed effects, alternative metrics, cross-period matching, same-author control (OCN, 374,601 tweets), rates
Treatment estimates are stable under added controls; against the authors' own un-noted tweets the effect vanishes, and engagement rates show no association; the global decline tracks newly fact-checked authors.
confounding and robustness analysisnegative-no-effect
RESAgainst the same authors' un-noted tweets (OCN), FCRH x Vis was non-significant: -0.669 (SE 0.422), -0.121 (0.305) retweets; -0.524 (0.429), -0.401 (0.290) likes; n=538 and 1,874.
FCRH x Vis = -0.669 (SE 0.422), -0.121 (SE 0.305) retweet count; -0.524 (SE 0.429), -0.401 (SE 0.290) like count; all n.s.; Observations = 538 (Pre-US), 1,874 (US-World); one-to-one matching caliper 0.0001, 269 of 313 (85.9%) and 937 of 976 (96%) F-CRH tweets matched; Vis and Month-Year effects also n.s.
Section 4.5.2, Table A10 · “The extra reduction in engagement within the F-CRH group is no longer significant compared to the baseline before the interventions”
negative-no-effect
informative
opposes HYP
RESBinomial regression of retweet and like rate (per impression) found FCRH non-significant: -0.014 (SE 0.249) and -0.388 (SE 0.256), robust to Month-Year effects, n=612 (306 of 328 F-CRH matched).
FCRH = -0.014 (SE 0.249), -0.031 (SE 0.263) retweet rate; -0.388 (SE 0.256), -0.433 (SE 0.253) like rate; all n.s.; Observations = 612; impression counts available from December 15, 2022; 306 of 328 (93.3%) F-CRH tweets matched to OCN
Section 4.5.2, Table 5 · “the retweet rate and like rate are not significantly associated with Community Notes”
negative-no-association
informative
opposes HYP
RESWith Musk, OldWriter and Month-Year controls, FCRH x Vis stayed -0.438** and -0.411* (Pre-US) and n.s. (US-World); Musk and OldWriter n.s.; Month-Year effects -1.186*** (2023/02), -1.229*** (2023/03).
Table A7: FCRH x Vis = -0.438** (SE 0.163), -0.102 (0.132), -0.411* (0.168), -0.083 (0.135); Musk = 0.097 to 0.213 n.s.; OldWriter = -0.110 to 0.033 n.s.; Month-Year 2023/01 -0.785**, 2023/02 -1.186***, 2023/03 -1.229***, 2023/04 -1.055*** (retweets); 2022/08-2022/12 all n.s.; Observations 5,019 and 11,821
Section 4.5.1, Tables A7-A9 · “the acquisition and possible selection bias between new and old note authors have no substantial effect on the engagement”
partial
informative
informs HYP
  • ISS Analysis is limited to English tweets; a multilingual evaluation of Community Notes is needed as the program establishes itself elsewhere. (untried · Section 5.3 Limitations and Future Research)
  • ISS Only aggregated retweet and like counts were available; per-tweet engagement timelines before and after a note appears remain unexamined. (next-step · Sections 5.1 and 5.3)
  • ISS 14% of fact-checked tweets were unavailable via the API (82.6% retrieval for CRH tweets); removed misleading tweets could mean the effect of Community Notes is underestimated. (open-question · Sections 3.1 and 5.3)
  • ISS A pre-selection mechanism that pushes likely-misleading tweets to contributors early in diffusion is proposed to cut fact-checking delay but not tested. (untried · Section 5.2 Practical Implications)

Extraction notes: Version: the text is the ACM version of record, Proc. ACM Hum.-Comput. Interact. Vol. 8, No. CSCW2, Article 428, November 2024, 52 pages, CC BY 4.0; received July 2023, revised January 2024, accepted March 2024. Author list in the text is Yuwei Chuai, Haoye Tian, Nicolas Pröllochs and Gabriele Lenzini, not the 'Chuai, Tilly, Pröllochs, Feuerriegel' given in my brief; I used the text. The paper poses a research question rather than a numbered hypothesis; the hyp quote is the authors' statement of the expected direction in Section 5.1 (framed via X/Twitter's pilot A/B test), which is my choice of the sentence that best states the tested expectation. Classifying the first-intervention F-CRH vs F-NCRH result (Table 2) as 'partial'/'informs' rather than 'positive'/'supports' is my reading of the authors' own reinterpretation: Section 4.2 says Community Notes 'seems to reduce the engagement', but Sections 4.3 and 4.5.2 show the same drop for non-misleading tweets and its disappearance against same-author controls. The 'inconclusive-controls-failed' class for the T-NMR placebo finding is also my reading (the placebo group showed a 'treatment effect', so the F-NCRH control comparison does not isolate the note display). The percentage effects and 95% CIs (35.5%, 33.2%, 39.5%, 35.5%) are the authors' own translations of the coefficients, copied verbatim; I did not derive them. Self-inconsistencies in the text: new-contributor count is 48,927 in Sections 4.1 and 5.1 but 48,928 in Section 4.5.1; Section 4.2 twice writes 'October 6, 2023' where the intervention date is October 6, 2022; Table A5 (short-delay subgroup) reports 1,716 and 6,463 observations in the like-count columns, identical to the unrestricted Table 3, while the retweet columns report 1,293 and 4,823, which looks like a copy error; Tables A11-A14 label the control group 'F-CNRH' where the text uses 'F-NCRH'. The single-treatment framework (Table A3: FCRH x Vis -0.487** retweets, -0.455** likes, n = 13,808; Table A6 placebo: FCRH vs T-NMR -0.079 and -0.037 n.s., n = 6,944) is consistent with the two-treatment results and is not listed as a separate finding. Also reported but not listed: misleading tweets receive fewer retweets (KS = 0.121, p < 0.001) and likes (KS = 0.133, p < 0.001) than not-misleading tweets regardless of the roll-out. All figures in the text are garbled glyph codes; I relied on captions and the tables. Dataset: 68,235 notes, 45,664 unique tweet IDs, 39,268 retrieved (86%), 36,077 English, 30,267 after the July 1, 2021 filter. Fairness condition for 'opposes': observational quasi-experiment with matched control groups, robust standard errors, reported sample sizes, parallel-trend tests and placebo tests; no seeds or runs apply.

LLM coding assistants and programmer productivity (Proc. ACM HCI, EICS, 2024)

Human-computer interaction · Proc. ACM Hum.-Comput. Interact. 8, EICS, 2024

A positive result from a controlled user study of code assistants.

Read left to right. The question (QUE) is addressed by 5 experiments (EXP), each producing results (RES), and each result bears on the hypothesis (HYP). 3 support it, 0 oppose it, 7 inform it. Issues (ISS) hang below: what the paper leaves open.

HYP, in the authors’ words (5.2 Usage Strategies): “While these results already look promising and support the hypothesis that AI will yield a considerable productivity benefit, we are likely only at the beginning of a shift in work practices in software development.”

Discourse graph of LLM coding assistants and programmer productivity (Proc. ACM HCI, EICS, 2024) que addresses exp-efficiency-activity que addresses exp-code-quality que addresses exp-satisfaction que addresses exp-communication-usage-patterns que addresses exp-individual-differences exp-efficiency-activity produces fnd-requirements-per-minute fnd-requirements-per-minute supports hyp exp-efficiency-activity produces fnd-characters-per-minute fnd-characters-per-minute supports hyp exp-efficiency-activity produces fnd-human-share-of-code fnd-human-share-of-code informs hyp exp-efficiency-activity produces fnd-task-completion-time fnd-task-completion-time informs hyp exp-code-quality produces fnd-correctness-no-difference fnd-correctness-no-difference consistent-with hyp exp-code-quality produces fnd-maintainability-no-difference fnd-maintainability-no-difference consistent-with hyp exp-code-quality produces fnd-copilot-more-comments fnd-copilot-more-comments informs hyp exp-satisfaction produces fnd-attrakdiff fnd-attrakdiff supports hyp exp-satisfaction produces fnd-self-assessment-and-overtrust fnd-self-assessment-and-overtrust informs hyp exp-communication-usage-patterns produces fnd-snippet-size-pattern fnd-snippet-size-pattern informs hyp exp-communication-usage-patterns produces fnd-browser-replaced fnd-browser-replaced informs hyp exp-individual-differences produces fnd-experience-only-affects-time fnd-experience-only-affects-time informs hyp exp-code-quality informs exp-efficiency-activity: The productivity gain came with code of the same correctness and maintainability as the baseline, so more output was not bought with worse code. exp-communication-usage-patterns informs exp-efficiency-activity: Both assistants reach about the same productivity through opposite acceptance patterns: many small inline snippets versus few large chat snippets with similar total AI characters. exp-satisfaction comparedWith exp-code-quality: Participants rated the quality of AI-assisted work higher although objective correctness and Maintainability Index did not differ; the authors read this as a degree of overtrust. exp-individual-differences extends exp-communication-usage-patterns: Only highly experienced participants mixed paradigms (questions as inline comments to Copilot, chatbot for rapid single lines), and they copied task descriptions into the chat, driving the snippet-size outliers. ISS · open questions and untried branches this path leaves behind QUE · positive Do LLM coding assistants (Copilot auto- complete, GPT-3 chat) raise programmer productivity across the SPACE dimensions compared with browser-only coding? Do LLM coding assistants (Copilot auto-complete, GPT-3 chat) raise programmer productivity across the SPACE dimensions compared with browser-only coding? HYP AI coding assistants, whether presented as inline auto-complete or as a chatbot, yield a considerable productivity benefit for programmers over conventional browser-supported coding. AI coding assistants, whether presented as inline auto-complete or as a chatbot, yield a considerable productivity benefit for programmers over conventional browser-supported coding. EXP · positive Within-subjects study (N=24, Latin Square, three 15-minute Python tasks): requirements per minute, typed characters per minute, human share of… Within-subjects study (N=24, Latin Square, three 15-minute Python tasks): requirements per minute, typed characters per minute, human share of code and task time, three conditions RES · positive Both AI conditions implemented significantly more requirements per minute than the baseline (Friedman chi2… Both AI conditions implemented significantly more requirements per minute than the baseline (Friedman chi2 = 6.583, df = 2, p = 0.037, Kendall's W = 0.137); authors state about 65% more requirements. RES · positive Participants typed significantly more characters per minute with both AI assistants than in the baseline… Participants typed significantly more characters per minute with both AI assistants than in the baseline (Friedman chi2 = 23.083, p < 0.001, W = 0.481; Copilot p < 0.001, chatbot p = 0.002). RES · positive The percentage of code written by the human fell significantly in both AI conditions (Friedman chi2 = 27.750, p <… The percentage of code written by the human fell significantly in both AI conditions (Friedman chi2 = 27.750, p < 0.001, W = 0.578; both pairwise p < 0.001) even as total code volume rose. RES · positive Task completion time differed significantly between each AI condition and the baseline (auto-complete p =… Task completion time differed significantly between each AI condition and the baseline (auto-complete p = 0.028, conversational p = 0.025); two participants finished AI tasks in under four minutes. EXP · inconclusive-underpowered Performance dimension: unit-test correctness of implemented requirements, Maintainability Index and comment density of the code produced under the… Performance dimension: unit-test correctness of implemented requirements, Maintainability Index and comment density of the code produced under the three support mechanisms (N=24) RES · inconclusive-underpowered Percent of correctly implemented requirements did not differ (Friedman chi2 = 0.636, df = 2, p = 0.728, W =… Percent of correctly implemented requirements did not differ (Friedman chi2 = 0.636, df = 2, p = 0.728, W = 0.013; 14, 12, 13 participants passed all tests); no power analysis reported. RES · inconclusive-underpowered Maintainability Index did not differ (ANOVA F = 0.065, p = 0.967; range 61 to 86, median 73 +/- 1 each; pairwise KS p… Maintainability Index did not differ (ANOVA F = 0.065, p = 0.967; range 61 to 86, median 73 +/- 1 each; pairwise KS p = 0.679, 0.898, 0.994); no power analysis reported. RES · partial Copilot code had significantly more comments than baseline code (Friedman chi2 = 8.583, p = 0.014, W = 0.179); th… Copilot code had significantly more comments than baseline code (Friedman chi2 = 8.583, p = 0.014, W = 0.179); the chatbot's rise was not significant and comments were descriptive, not explanatory. EXP · positive Satisfaction dimension: short AttrakDiff after each condition plus end-of-study Likert self-assessment of satisfaction, performance, communication and… Satisfaction dimension: short AttrakDiff after each condition plus end-of-study Likert self-assessment of satisfaction, performance, communication and efficiency (N=24) RES · positive AttrakDiff average differed across conditions (Friedman chi2 = 21.447, p < 0.001, W = 0.447); Copilot beat the… AttrakDiff average differed across conditions (Friedman chi2 = 21.447, p < 0.001, W = 0.447); Copilot beat the baseline on all three sub-scales, the chatbot on Hedonic Quality and Attractiveness only. RES · partial Self-rated Satisfaction, Performance, Communication and Efficiency all favoured the AI conditions (Friedman p… Self-rated Satisfaction, Performance, Communication and Efficiency all favoured the AI conditions (Friedman p < 0.001 each; effect sizes 0.456, 0.377, 0.377, 0.528) despite equal objective quality. EXP · positive Communication dimension: count, total characters and average size of accepted code snippets from the browser and from the AI assistant per condition, from… Communication dimension: count, total characters and average size of accepted code snippets from the browser and from the AI assistant per condition, from interaction logs (N=24) RES · positive Copilot users accepted more AI snippets (mean 12.6 vs 5.0, p < 0.001) but chatbot snippets were far larger (mean… Copilot users accepted more AI snippets (mean 12.6 vs 5.0, p < 0.001) but chatbot snippets were far larger (mean 205.4 vs 42.9 characters, p < 0.001); total AI characters did not differ significantly. RES · positive With an AI assistant only 4 (Copilot) and 2 (chatbot) of 24 used the browser; browser snippet count, volume and size… With an AI assistant only 4 (Copilot) and 2 (chatbot) of 24 used the browser; browser snippet count, volume and size fell vs baseline (p < 0.001 each); total snippets baseline vs chatbot p = 0.083. EXP · negative-no-association Post hoc analysis of prior experience and of outliers (72 outlier data points from 20 participants, 40 from six participants) across all metrics and… Post hoc analysis of prior experience and of outliers (72 outlier data points from 20 participants, 40 from six participants) across all metrics and conditions (N=24) RES · negative-no-association Prior experience significantly affected only task completion time (two-way ANOVA F = 7.029, df = 1, p = 0.01); no other… Prior experience significantly affected only task completion time (two-way ANOVA F = 7.029, df = 1, p = 0.01); no other productivity metric showed an effect of or correlation with experience. ISS · next-step The sample is young (mean age 26.8) and expertise affected only speed; studies of long-term AI users, senior developers and human-AI teams in the field are… The sample is young (mean age 26.8) and expertise affected only speed; studies of long-term AI users, senior developers and human-AI teams in the field are called for. ISS · open-question Tasks were pre-split into sub-tasks, so decomposing high-level requirements into programming steps, an essential part of development, was excluded and deferred… Tasks were pre-split into sub-tasks, so decomposing high-level requirements into programming steps, an essential part of development, was excluded and deferred to future studies. ISS · open-question The two AI conditions used related but not identical GPT-3-based models, and LLM output is probabilistic; whether the specific model shaped the results is… The two AI conditions used related but not identical GPT-3-based models, and LLM output is probabilistic; whether the specific model shaped the results is assumed, not tested. ISS · untried Hybrid interfaces, inline chatbot-style interaction within auto-complete or notebook-style conversations as executable cells, are proposed but… Hybrid interfaces, inline chatbot-style interaction within auto-complete or notebook-style conversations as executable cells, are proposed but untried.
  • supports positive finding
  • opposes a null, worse or failed result against a control or tuned baseline, with a reported test, interval or variance to show it is real
  • informs bears on the question without deciding the hypothesis
  • thin grey a relation between two experiments
Nodes, in reading order. Sources: Weber, Brandmaier, Schmidt & Mayer 2024, 10.1145/3661145; version of record from the ACM Digital Library, CC BY 4.0, read in full on 19 October 2026.
NodeTextTypeOutcomeEdge
EXPWithin-subjects study (N=24, Latin Square, three 15-minute Python tasks): requirements per minute, typed characters per minute, human share of code and task time, three conditions
Both AI conditions implemented significantly more requirements per minute and typed more characters per minute than the browser-only baseline, while the share of code written by the human fell.
controlled within-subjects user study (Efficiency and Activity dimensions of SPACE)positive
RESBoth AI conditions implemented significantly more requirements per minute than the baseline (Friedman chi2 = 6.583, df = 2, p = 0.037, Kendall's W = 0.137); authors state about 65% more requirements.
# of requirements implemented per minute, Friedman chi2 = 6.583, df = 2, p = 0.037, Kendall's W = 0.137; pairwise Wilcoxon vs baseline *** for both AI conditions (Fig. 9); 'about 65% more requirements with either AI assistant' (Discussion 5.1); N = 24
4.5 Efficiency; Table 2; Fig. 9; 5.1 · “both AI assistant conditions performed significantly better than the baseline with only the browser”
positive
informative
supports HYP
RESParticipants typed significantly more characters per minute with both AI assistants than in the baseline (Friedman chi2 = 23.083, p < 0.001, W = 0.481; Copilot p < 0.001, chatbot p = 0.002).
Character output per minute (human-typed), Friedman chi2 = 23.083, df = 2, p < 0.001, Kendall's W = 0.481; pairwise Wilcoxon, Bonferroni adjusted: auto-complete vs control p < 0.001, conversational vs control p = 0.002; N = 24
4.3 Activity; Table 2; Fig. 7 · “a significant increase in how many characters each of the participants typed out per minute in the two AI assistant conditions”
positive
informative
supports HYP
RESThe percentage of code written by the human fell significantly in both AI conditions (Friedman chi2 = 27.750, p < 0.001, W = 0.578; both pairwise p < 0.001) even as total code volume rose.
% of code created by human, Friedman chi2 = 27.750, df = 2, p < 0.001, Kendall's W = 0.578; pairwise Wilcoxon, Bonferroni adjusted: auto-complete p < 0.001, conversational p < 0.001; N = 24
4.3 Activity; Table 2; Fig. 7 · “the percentage of the code originating with the user decreased in the AI-assisted conditions”
positive
informative
informs HYP
RESTask completion time differed significantly between each AI condition and the baseline (auto-complete p = 0.028, conversational p = 0.025); two participants finished AI tasks in under four minutes.
Total time on tasks [sec], pairwise Wilcoxon test, Bonferroni adjusted: auto-complete vs control p = 0.028, conversational vs control p = 0.025; P19 just shy of four minutes (auto-complete), P24 three and a half minutes (auto-complete) and under three minutes (conversational); nominal limit 15 minutes per task
4.3 Activity; 4.5 Efficiency; Fig. 7 · “the AI assistants displaying significantly different task completion times than the control condition”
positive
informative
informs HYP
EXPPerformance dimension: unit-test correctness of implemented requirements, Maintainability Index and comment density of the code produced under the three support mechanisms (N=24)
Code correctness and Maintainability Index showed no significant difference between conditions, but with 24 participants and no power analysis the study cannot distinguish no effect from an underpowered test; only comment density rose with Copilot.
controlled within-subjects user study (Performance dimension of SPACE, objective code metrics)inconclusive-underpowered
RESPercent of correctly implemented requirements did not differ (Friedman chi2 = 0.636, df = 2, p = 0.728, W = 0.013; 14, 12, 13 participants passed all tests); no power analysis reported.
% of correctly implemented requirements, Friedman chi2 = 0.636, df = 2, p = 0.728, Kendall's W = 0.013; participants whose code fulfilled every testing criterion: control 14, auto-complete 12, conversational 13; N = 24
4.2 Performance; Table 2; Fig. 6 · “we could not determine any significant differences between the three groups”
inconclusive-underpowered
uninformative
consistent-with HYP
RESMaintainability Index did not differ (ANOVA F = 0.065, p = 0.967; range 61 to 86, median 73 +/- 1 each; pairwise KS p = 0.679, 0.898, 0.994); no power analysis reported.
Maintainability Index, repeated measures ANOVA F = 0.065, df = 2, p = 0.967; interval 61 to 86, median 73 +/- 1 per condition; pairwise Kolmogorov-Smirnov D = 0.208 / 0.167 / 0.125, p = 0.679 (control vs auto-complete), 0.898 (control vs conversational), 0.994 (auto-complete vs conversational); N = 24
4.2 Performance; Table 2; Table 3; Fig. 6 · “the Maintainability Index for all three groups follows the same distribution”
inconclusive-underpowered
uninformative
consistent-with HYP
RESCopilot code had significantly more comments than baseline code (Friedman chi2 = 8.583, p = 0.014, W = 0.179); the chatbot's rise was not significant and comments were descriptive, not explanatory.
Percentage of comments, Friedman chi2 = 8.583, df = 2, p = 0.014, Kendall's W = 0.179; pairwise Wilcoxon auto-complete vs control * (p < 0.05, Fig. 6); conversational vs control not significant; N = 24
4.2 Performance; Table 2; Fig. 6; 5.3 Code Quality · “the comments are more descriptive and less explanatory”
partial
informative
informs HYP
EXPSatisfaction dimension: short AttrakDiff after each condition plus end-of-study Likert self-assessment of satisfaction, performance, communication and efficiency (N=24)
Both AI assistants were rated significantly higher than the baseline on AttrakDiff and on all four self-assessment scales, with no significant difference between the two assistants.
controlled within-subjects user study (Satisfaction dimension of SPACE, questionnaires)positive
RESAttrakDiff average differed across conditions (Friedman chi2 = 21.447, p < 0.001, W = 0.447); Copilot beat the baseline on all three sub-scales, the chatbot on Hedonic Quality and Attractiveness only.
AttrakDiff (Avg.) Friedman chi2 = 21.447, df = 2, p < 0.001, Kendall's W = 0.447; Pragmatic Quality chi2 = 7.467, p = 0.024, W = 0.156; Hedonic Quality chi2 = 19.764, p < 0.001, W = 0.349; Attractiveness chi2 = 18.782, p < 0.001, W = 0.391; auto-complete vs baseline: Pragmatic p = 0.027 (Wilcoxon), Hedonic p < 0.001 (paired t-test), Attractiveness p = 0.001 (Wilcoxon); conversational vs baseline: Hedonic p < 0.001, Attractiveness p = 0.003, Pragmatic not significant; N = 24
4.1 Satisfaction; Table 2; Fig. 5 · “a consistent picture of both AI assistants similarly outperforming the baseline”
positive
informative
supports HYP
RESSelf-rated Satisfaction, Performance, Communication and Efficiency all favoured the AI conditions (Friedman p < 0.001 each; effect sizes 0.456, 0.377, 0.377, 0.528) despite equal objective quality.
Self-assessment Friedman tests: Satisfaction chi2 = 21.894, p < 0.001, effect size 0.456; Performance chi2 = 18.087, p < 0.001, 0.377; Communication chi2 = 18.083, p < 0.001, 0.377; Efficiency chi2 = 25.333, p < 0.001, 0.528; df = 2; two conversational-condition satisfaction outliers at 0 and 29 out of 100; N = 24
4.6 Self-Assessment; Table 4; Fig. 10; 5.1; 5.3 · “Participants tended to rate the performance and quality of the AI assistants as superior to the baseline, which may suggest a degree of overtrust”
partial
informative
informs HYP
EXPCommunication dimension: count, total characters and average size of accepted code snippets from the browser and from the AI assistant per condition, from interaction logs (N=24)
The two assistants deliver a similar volume of AI code through opposite patterns, many small Copilot snippets versus few large chatbot snippets, and both nearly replaced the browser as a source of code.
controlled within-subjects user study (Communication dimension of SPACE, interaction-log analysis)positive
RESCopilot users accepted more AI snippets (mean 12.6 vs 5.0, p < 0.001) but chatbot snippets were far larger (mean 205.4 vs 42.9 characters, p < 0.001); total AI characters did not differ significantly.
# of snippets (AI): auto-complete mean 12.6, median 11.5; conversational mean 5.0, median 4.5; p < 0.001, Wilcoxon, Bonferroni adjusted. # of characters (AI): auto-complete mean 514.0, median 482.0; conversational mean 818.4, median 596.5; not significant. Avg. snippet size (AI): auto-complete mean 42.9, median 41.8; conversational mean 205.4, median 110.9; p < 0.001. Avg. snippet size from any source: control mean 36.1, median 31.2; auto-complete mean 42.4, median 41.8; conversational mean 204.6, median 110.9, all pairwise significant; N = 24
4.4 Communication; Table 2; Fig. 8 · “code snippets from the chatbot tend to be larger, while the auto-complete interface seems to favor more but smaller code snippets”
positive
informative
informs HYP
RESWith an AI assistant only 4 (Copilot) and 2 (chatbot) of 24 used the browser; browser snippet count, volume and size fell vs baseline (p < 0.001 each); total snippets baseline vs chatbot p = 0.083.
Browser users: 4 of 24 in auto-complete, 2 of 24 in conversational; # of snippets, # of characters and avg. snippet size (Browser) vs control p < 0.001 each, Friedman chi2 = 41.325, Kendall's W = 0.861; # of snippets (Total): control vs auto-complete p < 0.0001, auto-complete vs conversational p < 0.001, control vs conversational p = 0.083 (Wilcoxon, Bonferroni adjusted); N = 24
4.4 Communication; Table 2; Fig. 8; 5.2 · “the AI assistants essentially replaced the browser as the source of information”
positive
informative
informs HYP
EXPPost hoc analysis of prior experience and of outliers (72 outlier data points from 20 participants, 40 from six participants) across all metrics and conditions (N=24)
Prior experience affected only task completion time; otherwise individual usage strategies, not expertise, explained the outliers.
exploratory post hoc analysis of moderators and outliersnegative-no-association
RESPrior experience significantly affected only task completion time (two-way ANOVA F = 7.029, df = 1, p = 0.01); no other productivity metric showed an effect of or correlation with experience.
Task completion time by experience, two-way ANOVA F = 7.029, df = 1, p = 0.01; all other metrics no significant effect; 72 outliers (outside 1.5 IQR) from 20 participants, 40 of them from P2, P4, P14, P19, P22, P24; N = 24
4.7 Qualitative Feedback; 4.8 Individual Differences; 5.4 Limitations · “For all other metrics, there was no significant effect of or notable correlations with the prior experience across the whole group.”
negative-no-association
informative
informs HYP
  • ISS The sample is young (mean age 26.8) and expertise affected only speed; studies of long-term AI users, senior developers and human-AI teams in the field are called for. (next-step · 5.4 Limitations)
  • ISS Tasks were pre-split into sub-tasks, so decomposing high-level requirements into programming steps, an essential part of development, was excluded and deferred to future studies. (open-question · 5.4 Limitations)
  • ISS The two AI conditions used related but not identical GPT-3-based models, and LLM output is probabilistic; whether the specific model shaped the results is assumed, not tested. (open-question · 5.4 Limitations)
  • ISS Hybrid interfaces, inline chatbot-style interaction within auto-complete or notebook-style conversations as executable cells, are proposed but untried. (untried · 5.2 Usage Strategies)

Extraction notes: Version: the text is the version of record (ACM Reference Format with article 256, Proc. ACM HCI vol. 8 EICS, June 2024; 'First Submitted February 2024; Accepted April 2024'; CC BY 4.0). The paper states no numbered hypotheses or research questions; the hypothesis quoted is the authors' own phrase in Discussion 5.2 ('support the hypothesis that AI will yield a considerable productivity benefit'), and the question label is my paraphrase of the abstract and introduction. Design: within-subjects, 29 recruited, 5 excluded (some for using ChatGPT in the browser during the baseline), N = 24; three Python tasks (text analysis, CSV transformation, PDF editing) with a 15-minute limit each, tool-task combination and order permuted by Latin Square; tests chosen by Shapiro-Wilk, Friedman with Wilcoxon post hoc or repeated-measures ANOVA with t-test post hoc, Bonferroni adjusted; effect sizes are Kendall's W or eta-squared from Table 2 (Table 2 gives no effect size for the Maintainability Index). Inferences of mine: (1) the valence 'opposes' on the two code-quality nulls is my application of the brief's rule, since Performance is one of the five SPACE dimensions of productivity and the study has a control condition, a reported test and N; the authors themselves frame the null as reassuring ('the AI assistants produce code that is about equally good'), and no power analysis is reported, so a reviewer may prefer inconclusive-underpowered; (2) the direction of the task-completion-time difference is not stated in the text (only 'significantly different'); the outlier descriptions (P19, P24 finishing in under four minutes) and Fig. 7 imply the AI conditions were faster, but I did not assert it; (3) the headline 'about 65% more requirements' appears only as a sentence in Discussion 5.1 with no table value behind it. Ambiguities and self-inconsistencies in the text: Fig. 5, 7 and 8 captions print the legend as '**: p < 0.001' where '***' is meant; the text writes 'p =< 0.001' and 'p =< 0.0001' in 4.4 (PDF garble of '<'); quoted participant IDs run up to P29 because excluded participants kept their numbers; 2.3 reports Peng et al.'s gain as 'more than half' and Table 1 as 55.8% while 5.1 cites 56%; the auto-complete average AI snippet size is 42.9 (AI source only) versus 42.4 (all sources), which are different metrics, not a contradiction; 'control' and 'Baseline' are used interchangeably. Behavioural observations recorded in the paper and not given their own finding: P19 copied the feature description, let Copilot generate most of the code and did not thoroughly verify it; experienced users (P2, P14, P24) used Copilot line by line and the chatbot for whole functions while P19 did the reverse; five participants struggled to read Copilot output quickly, two saw clearly incorrect code, six criticised the chatbot's context switch and three its verbosity; 21 participants named positives for each AI condition against four for the baseline. Data and scripts are stated to be on OSF (view-only link in the Open Science section). Revision at the coordinator's request: the two code-quality nulls (percent correctly implemented requirements, Maintainability Index) were downgraded from negative-no-effect / opposes to inconclusive-underpowered / uninformative / consistent-with, because the paper reports no power analysis, equivalence test or interval tight enough to exclude the effect of interest, so a p-value from 24 participants cannot tell no effect from an underpowered test; numbers, locators and quotes are unchanged.

AI Ghostwriter Effect: ownership versus declared authorship for AI-generated text (ACM TOCHI, 2024)

Human-computer interaction · ACM Trans. Comput.-Hum. Interact. 31(2), 2024

A positive result with a null inside it: the effect holds in two studies, and personalisation does not change it.

Read left to right. The question (QUE) is addressed by 4 experiments (EXP), each producing results (RES), and each result bears on the hypothesis (HYP). 3 support it, 0 oppose it, 9 inform it. Issues (ISS) hang below: what the paper leaves open.

HYP, in the authors’ words (Section 3, Research Questions and Hypotheses (H1.1 and H1.2)): “Participants will consider the AI (and not themselves) to be the owner of personalized AI-generated texts but They will not declare AI authorship or AI support when publishing personalized AI-generated texts.”

Discourse graph of AI Ghostwriter Effect: ownership versus declared authorship for AI-generated text (ACM TOCHI, 2024) que addresses study1-ownership-vs-declaration que addresses study1-influence-control-ownership que addresses study1-user-experience que addresses study2-human-vs-ai-ghostwriter study1-ownership-vs-declaration produces s1-im-ownership s1-im-ownership supports hyp study1-ownership-vs-declaration produces s1-declared-authorship s1-declared-authorship supports hyp study1-ownership-vs-declaration produces s1-personalization-null s1-personalization-null informs hyp study1-ownership-vs-declaration produces s1-personalization-manipulation-check s1-personalization-manipulation-check informs hyp study1-influence-control-ownership produces s1-control-by-im s1-control-by-im informs hyp study1-influence-control-ownership produces s1-control-predicts-ownership s1-control-predicts-ownership informs hyp study1-user-experience produces s1-getting-worst-ux s1-getting-worst-ux informs hyp study2-human-vs-ai-ghostwriter produces s2-ownership-human-vs-ai s2-ownership-human-vs-ai informs hyp study2-human-vs-ai-ghostwriter produces s2-declaration-human-vs-ai s2-declaration-human-vs-ai informs hyp study2-human-vs-ai-ghostwriter produces s2-ghostwriter-effect-replication s2-ghostwriter-effect-replication supports hyp study2-human-vs-ai-ghostwriter produces s2-control-no-difference s2-control-no-difference informs hyp study2-human-vs-ai-ghostwriter produces s2-leadership-mixed s2-leadership-mixed informs hyp study1-ownership-vs-declaration informs study2-human-vs-ai-ghostwriter: The null personalization result let Study 2 drop fine-tuning and use placebo-personalization as a Wizard-of-Oz; Study 1's free-text 'random' entry motivated the six pre-defined author labels. study1-influence-control-ownership informs study2-human-vs-ai-ghostwriter: Getting was chosen as the sole Study 2 method because it had the lowest sense of ownership and the most AI-author mentions in Study 1. study2-human-vs-ai-ghostwriter confirms study1-ownership-vs-declaration: Pre-registered replication in a larger sample (96 vs 30) reproduced the ownership-declaration discrepancy, though with a much smaller share omitting the AI once a menu option existed. study1-user-experience comparedWith study1-influence-control-ownership: The same four Interaction Methods: the method with least user influence (Getting) was both lowest in control/leadership and worst in hedonic quality and appeal. ISS · open questions and untried branches this path leaves behind QUE · positive Do users who feel personalized AI- generated text belongs to the AI still publish it under their own name, and does personalization or user influence change this? Do users who feel personalized AI-generated text belongs to the AI still publish it under their own name, and does personalization or user influence change this? HYP AI Ghostwriter Effect: participants consider the AI, not themselves, the owner of personalized AI-generated text, yet do not declare AI authorship or AI support when publishing it. AI Ghostwriter Effect: participants consider the AI, not themselves, the owner of personalized AI-generated text, yet do not declare AI authorship or AI support when publishing it. EXP · positive Study 1 (n = 30, July 2022): 4 Interaction Methods (Writing, Editing, Choosing, Getting; within) x fine-tuned vs placebo personalization (between) on… Study 1 (n = 30, July 2022): 4 Interaction Methods (Writing, Editing, Choosing, Getting; within) x fine-tuned vs placebo personalization (between) on ownership and author field RES · positive Interaction Method strongly affected 'To whom should this text belong', F(2.02, 56.58) = 55.75, p < .001, eta2p = .67… Interaction Method strongly affected 'To whom should this text belong', F(2.02, 56.58) = 55.75, p < .001, eta2p = .67; all AI methods differed from Writing (p < .001), not from each other. RES · partial Interaction Method affected how often 'AI' appeared in the author field, Cochran's Q(3) = 18.54, p < .001, but… Interaction Method affected how often 'AI' appeared in the author field, Cochran's Q(3) = 18.54, p < .001, but only six to seven of 30 participants per AI method mentioned AI at all. RES · negative-no-effect True fine-tuning versus placebo personalization had no effect on ownership, F(1, 28) = 0.52, p = .477… True fine-tuning versus placebo personalization had no effect on ownership, F(1, 28) = 0.52, p = .477, eta2p = .02; a Bayesian t-test favoured the no-difference model 2.38 to 1. RES · positive Personalization worked: cosine similarity between a participant's own and generated texts was .77 (SD .04)… Personalization worked: cosine similarity between a participant's own and generated texts was .77 (SD .04) with fine-tuning vs .72 (SD .06) for placebo, t(25.72) = -2.89, p = .008, d = -1.06. EXP · positive Study 1 (n = 30): whether the four Interaction Methods shift the sense of control and leadership (H2.1, H2.2) and whether those predict the sense of… Study 1 (n = 30): whether the four Interaction Methods shift the sense of control and leadership (H2.1, H2.2) and whether those predict the sense of ownership (linear mixed models) RES · positive Interaction Method changed the sense of control, F(2.25, 62.95) = 28.18, p < .001, eta2p = .50; all pairwise… Interaction Method changed the sense of control, F(2.25, 62.95) = 28.18, p < .001, eta2p = .50; all pairwise differences significant except Getting vs Choosing (p > .99). RES · positive In a linear mixed model, sense of control predicted ownership, beta = 0.21, 95% CI [0.05, 0.37], t(109) =… In a linear mixed model, sense of control predicted ownership, beta = 0.21, 95% CI [0.05, 0.37], t(109) = 2.57, p = 0.012 (conditional R2 = 65%); leadership likewise, beta = 0.21, p = 0.015. EXP · positive Study 1 (n = 30): AttrakDiff user experience of the four Interaction Methods (pragmatic quality, hedonic identity, hedonic stimulation, appeal) Study 1 (n = 30): AttrakDiff user experience of the four Interaction Methods (pragmatic quality, hedonic identity, hedonic stimulation, appeal) RES · positive Getting scored lowest on hedonic identity (M = 3.74, SD = 1.28) vs Writing (M = 4.78, SD = 0.88), Choosing… Getting scored lowest on hedonic identity (M = 3.74, SD = 1.28) vs Writing (M = 4.78, SD = 0.88), Choosing (4.47) and Editing (4.81), F(2.23, 62.32) = 8.50, p < .001. EXP · partial Study 2 (pre-registered, n = 96, Dec 2022): within-subject Wizard-of-Oz, the same placebo-personalized postcard framed as written by an AI or by human… Study 2 (pre-registered, n = 96, Dec 2022): within-subject Wizard-of-Oz, the same placebo-personalized postcard framed as written by an AI or by human ghostwriter 'Sasha' RES · positive Participants attributed more ownership to themselves when the ghostwriter was presented as AI rather than human, t(95… Participants attributed more ownership to themselves when the ghostwriter was presented as AI rather than human, t(95) = -2.05, p = .043, d = -0.21; Wilcoxon W = 1095, p = .018, r = .10. RES · positive With a pre-defined author menu, 71 of 96 (73.9%) named the AI ghostwriter versus 79 (82.3%) naming the human one; AI was… With a pre-defined author menu, 71 of 96 (73.9%) named the AI ghostwriter versus 79 (82.3%) naming the human one; AI was mentioned significantly less often, McNemar chi2(1) = 31.92, p < .001. RES · partial Weak replication: ownership and declaring AI correlated only rs = .24, p = .017 (human rs = .26, p = .011); 25 o… Weak replication: ownership and declaring AI correlated only rs = .24, p = .017 (human rs = .26, p = .011); 25 of 96 still omitted the AI despite a menu option, vs about 80% in Study 1. RES · negative-no-effect Sense of control did not differ between AI and human ghostwriter, t(95) = 0.28, p = .784, d = 0.03; a Bayesian t-test… Sense of control did not differ between AI and human ghostwriter, t(95) = 0.28, p = .784, d = 0.03; a Bayesian t-test favoured no difference about 8.5 to 1. RES · inconclusive Sense of leadership showed no mean difference, t(95) = -1.10, p = .274, d = -0.11, but a significant rank… Sense of leadership showed no mean difference, t(95) = -1.10, p = .274, d = -0.11, but a significant rank difference, Wilcoxon W = 876, p = .021, r = .12, higher for the AI ghostwriter. ISS · next-step The postcard task is artificial and short; the effect should be replicated in writing tasks that require longer, more nuanced texts and that are actuall… The postcard task is artificial and short; the effect should be replicated in writing tasks that require longer, more nuanced texts and that are actually sent to someone. ISS · open-question Fine-tuning used fewer prompt-completion pairs than OpenAI recommends and Study 2 had no true personalization; whether better personalization changes the… Fine-tuning used fewer prompt-completion pairs than OpenAI recommends and Study 2 had no true personalization; whether better personalization changes the effect is untested. ISS · open-question AI was declared by about 20% with a free-text author field but about 70% with a selection menu; how to design declaration interfaces so AI… AI was declared by about 20% with a free-text author field but about 70% with a selection menu; how to design declaration interfaces so AI contributions are declared is open. ISS · untried Whether the ownership-declaration discrepancy also holds for non- personalized AI writing contexts has not been investigated. Whether the ownership-declaration discrepancy also holds for non-personalized AI writing contexts has not been investigated.
  • supports positive finding
  • opposes a null, worse or failed result against a control or tuned baseline, with a reported test, interval or variance to show it is real
  • informs bears on the question without deciding the hypothesis
  • thin grey a relation between two experiments
Nodes, in reading order. Sources: Draxler, Werner, Lehmann, Hoppe, Schmidt, Buschek & Welsch 2024, 10.1145/3637875; version of record from the ACM Digital Library, CC BY 4.0, read in full on 19 October 2026.
NodeTextTypeOutcomeEdge
EXPStudy 1 (n = 30, July 2022): 4 Interaction Methods (Writing, Editing, Choosing, Getting; within) x fine-tuned vs placebo personalization (between) on ownership and author field
All AI methods lowered the sense of ownership relative to Writing, yet at most 7 of 30 participants per AI method named the AI as author; personalization changed nothing.
within-between mixed-design online user study with repeated-measures ANOVA, Cochran's Q and Bayesian t-testspositive
RESInteraction Method strongly affected 'To whom should this text belong', F(2.02, 56.58) = 55.75, p < .001, eta2p = .67; all AI methods differed from Writing (p < .001), not from each other.
repeated-measures ANOVA, Interaction Method main effect F = 55.75, df (2.02, 56.58) Greenhouse-Geisser corrected, p < .001, eta2p = .67; n = 30; post-hoc all AI methods vs Writing p < .001, AI methods among themselves p > .05; non-parametric check F(3, 84) = 45.24, p < .05
Section 4.2, H1.1 & H3: Sense of Ownership; Table 3; Figure 2 · “All AI-related Interaction Methods differed from the Writing condition (all p < .001), but none of the AI-related Interaction Methods differed from each other”
positive
informative
supports HYP
RESInteraction Method affected how often 'AI' appeared in the author field, Cochran's Q(3) = 18.54, p < .001, but only six to seven of 30 participants per AI method mentioned AI at all.
Cochran's Q-test on binarized mention of AI, Q(3) = 18.54, p < .001; n = 30; 6-7 participants per AI method (Editing, Choosing, Getting) mentioned AI; planned comparisons Writing vs each other method all p < .03; Editing vs Getting vs Choosing pairwise all p > .05; paper also states 'a max. of 23.3% in Study 1'
Section 4.2, H1.2: Declaration of Authorship; Figure 3 · “Only between six and seven participants per Interaction Method (except Writing) mentioned AI.”
partial
informative
supports HYP
RESTrue fine-tuning versus placebo personalization had no effect on ownership, F(1, 28) = 0.52, p = .477, eta2p = .02; a Bayesian t-test favoured the no-difference model 2.38 to 1.
Personalization main effect F(1, 28) = 0.52, p = .477, eta2p = .02; Interaction Method x Personalization F(2.02, 56.58) = 0.48, p = .625, eta2p = .02; Bayes factor 2.38 for the null (default Cauchy prior sqrt(2)/2); n = 30 (two groups, 'half the participants' each)
Section 4.2, H1.1 & H3: Sense of Ownership; Table 3 · “the model assuming no difference is 2.38 times more like than the model assuming differences in means given the priors”
negative-no-effect
informative
informs HYP
RESPersonalization worked: cosine similarity between a participant's own and generated texts was .77 (SD .04) with fine-tuning vs .72 (SD .06) for placebo, t(25.72) = -2.89, p = .008, d = -1.06.
cosine similarity (tidytext), true personalization M = .77, SD = .04 vs placebo M = .72, SD = .06; Welch t(25.72) = -2.89, p = .008, d = -1.06; Table 1 Likert 'contains words/phrases I usually use' MD 5.07 (SD 1.67) vs 4.20 (SD 1.90)
Section 4.2, Manipulation Check: Personalization of the Generated Texts; Table 1 · “the cosine similarity was larger for the true personalization group (M = .77, SD = .04) compared to the placebo-personalization condition”
positive
informative
informs HYP
EXPStudy 1 (n = 30): whether the four Interaction Methods shift the sense of control and leadership (H2.1, H2.2) and whether those predict the sense of ownership (linear mixed models)
More influence over the text raised perceived control and leadership, and both positively predicted ownership (beta = 0.21 each); personalization again had no effect.
manipulation check plus linear mixed model regression with participant random effectpositive
RESInteraction Method changed the sense of control, F(2.25, 62.95) = 28.18, p < .001, eta2p = .50; all pairwise differences significant except Getting vs Choosing (p > .99).
repeated-measures ANOVA on 'Who was in control over the content', F(2.25, 62.95) = 28.18, p < .001, eta2p = .50, Greenhouse-Geisser corrected; Bonferroni t-tests all p < .05 except Getting vs Choosing p > .99; Personalization F(1, 28) = 1.05, p = .315; Bayes factor 1.98 for the null; n = 30
Section 4.2, H2.1: Sense of Control; Table 3; Figure 4 · “Bonferroni-corrected t-tests revealed significant differences between all comparisons (all p < .05), with the exception of the comparison between Getting and Choosing (p > .99”
positive
informative
informs HYP
RESIn a linear mixed model, sense of control predicted ownership, beta = 0.21, 95% CI [0.05, 0.37], t(109) = 2.57, p = 0.012 (conditional R2 = 65%); leadership likewise, beta = 0.21, p = 0.015.
LMM with participant random effect: control F(1, 101.55) = 6.47, p = .02; beta = 0.21, 95% CI [0.05, 0.37], t(109) = 2.57, p = 0.012; standardized beta_z = 0.20, 95% CI [0.05, 0.36]; conditional R2 = 65%, marginal R2 = 55%. Leadership model: beta = 0.21, 95% CI [0.04, 0.37], t(109) = 2.46, p = 0.015; conditional R2 = 64%; n = 30 x 4 methods
Section 4.2, H2.1 and H2.2 (linear mixed model paragraphs); Figure 5 · “There was a statistically significant and positive effect (beta = 0.21, 95% CI [0.05, 0.37], t(109) = 2.57, p = 0.012”
positive
informative
informs HYP
EXPStudy 1 (n = 30): AttrakDiff user experience of the four Interaction Methods (pragmatic quality, hedonic identity, hedonic stimulation, appeal)
Getting, the method with most AI influence, was rated worst on identity and appeal; personalization had no main effect on any AttrakDiff scale.
secondary outcome, repeated-measures ANOVA with Bonferroni post-hoc comparisonspositive
RESGetting scored lowest on hedonic identity (M = 3.74, SD = 1.28) vs Writing (M = 4.78, SD = 0.88), Choosing (4.47) and Editing (4.81), F(2.23, 62.32) = 8.50, p < .001.
AttrakDiff hedonic quality-identity: Interaction Method F(2.23, 62.32) = 8.50, p < .001, eta2p = .23; Getting M = 3.74, SD = 1.28; Writing M = 4.78, SD = 0.88; Choosing M = 4.47, SD = 1.21; Editing M = 4.81, SD = 1.06. Appeal: F(3, 84) = 8.07, p < .001, eta2p = .22; Getting M = 3.99, SD = 1.66 vs Writing M = 5.24, SD = 0.89, Choosing M = 4.94, SD = 1.39, Editing M = 5.13, SD = 1.38. Personalization on all scales p > .05; n = 30
Section 4.3, User Experience; Table 3; Figure 7 · “the Getting (M = 3.74, SD = 1.28) interaction was perceived worse than Writing (M = 4.78, SD = 0.88), Choosing”
positive
informative
informs HYP
EXPStudy 2 (pre-registered, n = 96, Dec 2022): within-subject Wizard-of-Oz, the same placebo-personalized postcard framed as written by an AI or by human ghostwriter 'Sasha'
The ownership-declaration discrepancy replicated but shrank (about 26% of participants omitted the AI vs about 80% in Study 1); people felt more ownership of, and credited less often, the AI ghostwriter than the human one.
pre-registered replication and extension; paired Welch t-tests, Wilcoxon, McNemar chi-square, Spearman correlation, Bayes factorspartial
RESParticipants attributed more ownership to themselves when the ghostwriter was presented as AI rather than human, t(95) = -2.05, p = .043, d = -0.21; Wilcoxon W = 1095, p = .018, r = .10.
paired Welch-corrected t-test on 'To whom should this text belong', t(95) = -2.05, p = .043, Cohen's d = -0.21; Wilcoxon W = 1095, p = .018, r = .10 (normality violated p < .01); n = 96, within-subject
Section 5.2, H4: Differences in Sense of Ownership; Table 4; Figure 8 · “People attributed more ownership to themselves when the ghostwriter was presented as an AI, compared to when it was presented as a human”
positive
informative
informs HYP
RESWith a pre-defined author menu, 71 of 96 (73.9%) named the AI ghostwriter versus 79 (82.3%) naming the human one; AI was mentioned significantly less often, McNemar chi2(1) = 31.92, p < .001.
Table 5: AI condition mention 71 (73.9%), no mention 25 (26.0%); Human condition mention 79 (82.3%), no mention 17 (17.7%); McNemar chi2(1) = 31.92, p < .001; n = 96; mandatory-marking vote: human 63 (65.6%) yes vs AI 59 (61.5%) yes
Section 5.2, H5: Differences in Authorship Declaration; Table 5 · “they mentioned AI significantly less often, chi2 (1) = 31.92, p < .001, than mentioning "Sasha" or any entity other than themselves”
positive
informative
informs HYP
RESWeak replication: ownership and declaring AI correlated only rs = .24, p = .017 (human rs = .26, p = .011); 25 of 96 still omitted the AI despite a menu option, vs about 80% in Study 1.
Spearman rank correlation ownership vs AI-author mention rs = .24, p = .017; human ghostwriter rs = .26, p = .011; 25 (26.0%) of 96 did not mention AI; paper: 'about 71.3% in Study 2 versus a max. of 23.3% in Study 1' mentioned AI
Section 5.2, H6: AI Ghostwriter Effect; Section 7, Conclusion · “there is no direct 1:1 mapping to the sense of ownership, and there is no strong correlation, supporting H6”
partial
informative
supports HYP
RESSense of control did not differ between AI and human ghostwriter, t(95) = 0.28, p = .784, d = 0.03; a Bayesian t-test favoured no difference about 8.5 to 1.
Welch-corrected paired t(95) = 0.28, p = .784, d = 0.03; Bayes factor about 8.5 for the null (default priors); n = 96
Section 5.2, Sense of Control and Leadership; Table 4; Figure 9; footnote 21 · “the model assuming no differences is about 8.5 times more likely than the model assuming a difference”
negative-no-effect
informative
informs HYP
RESSense of leadership showed no mean difference, t(95) = -1.10, p = .274, d = -0.11, but a significant rank difference, Wilcoxon W = 876, p = .021, r = .12, higher for the AI ghostwriter.
Welch-corrected t(95) = -1.10, p = .274, d = -0.11; Wilcoxon W = 876, p = .021, r = .12; normality violated p < .01; n = 96
Section 5.2, Sense of Control and Leadership; Table 4; Figure 10 · “there was a significant effect when comparing ranks with a Wilcoxon test, which was probably due to the large skew in the data”
inconclusive
uninformative
informs HYP
  • ISS The postcard task is artificial and short; the effect should be replicated in writing tasks that require longer, more nuanced texts and that are actually sent to someone. (next-step · Section 6.5, Limitations (First))
  • ISS Fine-tuning used fewer prompt-completion pairs than OpenAI recommends and Study 2 had no true personalization; whether better personalization changes the effect is untested. (open-question · Section 6.5, Limitations (Second))
  • ISS AI was declared by about 20% with a free-text author field but about 70% with a selection menu; how to design declaration interfaces so AI contributions are declared is open. (open-question · Section 6.5, Limitations (Third); Section 6.3)
  • ISS Whether the ownership-declaration discrepancy also holds for non-personalized AI writing contexts has not been investigated. (untried · Section 6.5, Limitations (Sixth))

Extraction notes: VERSION: the text is the ACM version of record, ACM Transactions on Computer-Human Interaction vol. 31 no. 2, Article 25, publication date February 2024, CC BY 4.0; the task brief labelled it 2023 but the text itself says 2024 throughout, so the title uses 2024. Study 1 ran July 2022, Study 2 December 2022, pre-registered at aspredicted.org/t4xd8.pdf. INFERENCES OF MINE: (a) I took H1 (H1.1 + H1.2, the AI Ghostwriter Effect) as the graph hypothesis, so findings on H2 (control/leadership), H3 (personalization), H4/H5 (human vs AI ghostwriter) and user experience carry valence 'informs' even where they support the paper's own secondary hypotheses; the personalization null (s1-personalization-null) is classed negative-no-effect because it had a working manipulation check and a between-group test, but note the paper's own H3 predicted exactly this null, so relative to H3 it is a confirmation, and the Bayes factor of 2.38 is weak evidence with only 'half' of 30 (I infer 15) per group. (b) outcomeClass 'partial' for s1-declared-authorship follows the paper's own words 'partial support for H1.2'; 'partial' for s2-ghostwriter-effect-replication is my reading of the authors' statement that the effect was 'reduced when switching from open-ended author declaration fields to predefined response suggestions' (Section 7) together with rs = .24. (c) The 'roughly 80% omitting the AI in Study 1' in s2-ghostwriter-effect-replication is my paraphrase of the paper's 'less than one-fifth of the participants declared the AI as an author' (Section 6) and 'only about 20%' (Section 6.5); the paper also gives 'a max. of 23.3%' (Section 5.2) and 'six and seven participants per Interaction Method' (7/30 = 23.3%), so 'less than one-fifth' is slightly inconsistent with its own counts. SELF-INCONSISTENCIES IN THE PAPER: (1) Section 5.2 says 'about 71.3% in Study 2' mentioned AI, but Table 5 reports 71 (73.9%); 71/96 is 73.96%, so 71.3% looks like a slip. (2) In Table 3 the 'Sense of leadership' rows are numerically identical to the 'Sense of control' rows (F = 28.18, df (2.25, 62.95), eta2p .50; Personalization F 1.05, p .315; interaction F 0.60, p .570), which looks like a copy error; the non-parametric leadership check in footnote 19 gives a different F(3, 84) = 30.26, versus 45.24 for ownership. (3) The leadership LMM reports F(3, 95.65) = 5.93 for a single continuous predictor (3 numerator df is odd); copied as given. (4) The H5 paragraph says 'We found differences in the declaration of authorship (H3)', apparently meaning H5. (5) Table 4 control row shows 't (95) 0.28 .784, 0 .03' with no Wilcoxon entry; I read d = 0.03. (6) Table 2 (Likert medians) is garbled by PDF extraction (e.g. '42 . 1 5'), so I did not use it. NOT FOUND IN TEXT: numeric means or SDs of the ownership, control and leadership visual-analog scales (-50 me to +50 AI) for any condition; they appear only in Figures 2-6 and 8-10, so the direction findings rest on F/t statistics and the authors' prose. Group sizes for true vs placebo personalization are given only as 'half the participants'. Percentages in Table 5 for the no-mention AI cell (26.0%) versus 25/96 = 26.04% are consistent. The Study 1 ownership rating was collected after all four methods, which the authors themselves flag as a possible contamination of the Writing baseline (Section 5 intro). Supplementary results (text remembrance, open-ended answers, attitudes to AI) are on OSF and not in the text.

HIVE-COTE vs Flat-COTE and CNNs for time series classification (ACM TKDD, 2018)

Data mining · ACM Trans. Knowl. Discov. Data 12(5), 2018

A positive result that starts with a negative one: two convolutional networks lose to the existing ensemble before the new ensemble beats it.

Read left to right. The question (QUE) is addressed by 5 experiments (EXP), each producing results (RES), and each result bears on the hypothesis (HYP). 3 support it, 0 oppose it, 9 inform it. Issues (ISS) hang below: what the paper leaves open.

HYP, in the authors’ words (Abstract): “We demonstrate that HIVE-COTE is significantly more accurate than Flat-COTE (and all other TSC algorithms that we are aware of) over 100 resamples of 85 TSC problems and is the new state of the art for TSC.”

Discourse graph of HIVE-COTE vs Flat-COTE and CNNs for time series classification (ACM TKDD, 2018) que addresses flat-cote-vs-cnns que addresses hive-vs-flat-cote-ucr85 que addresses module-validation-hesca-rise que addresses simulated-datasets que addresses case-studies flat-cote-vs-cnns produces flat-cote-beats-benchmark-cnn flat-cote-beats-benchmark-cnn informs hyp flat-cote-vs-cnns produces flat-cote-beats-mcnn-44 flat-cote-beats-mcnn-44 informs hyp flat-cote-vs-cnns produces hive-cote-beats-mcnn-44 hive-cote-beats-mcnn-44 supports hyp hive-vs-flat-cote-ucr85 produces hive-cote-headline-ucr85 hive-cote-headline-ucr85 supports hyp hive-vs-flat-cote-ucr85 produces flat-cote-ahead-on-some-datasets flat-cote-ahead-on-some-datasets informs hyp module-validation-hesca-rise produces hesca-vs-constituents-uci72 hesca-vs-constituents-uci72 informs hyp module-validation-hesca-rise produces rise-vs-spectral-hesca rise-vs-spectral-hesca informs hyp module-validation-hesca-rise produces time-complexity-unchanged time-complexity-unchanged informs hyp simulated-datasets produces hive-beats-flat-on-1000-simulations hive-beats-flat-on-1000-simulations supports hyp simulated-datasets produces hive-worse-than-best-on-interval-spectral hive-worse-than-best-on-interval-spectral informs hyp case-studies produces ethanol-st-hesca-beats-hive ethanol-st-hesca-beats-hive informs hyp case-studies produces vowel-rise-beats-hive vowel-rise-beats-hive informs hyp flat-cote-vs-cnns informs hive-vs-flat-cote-ucr85: Confirms Flat-COTE, not a CNN, as the state of the art that HIVE-COTE must beat; the same 44-dataset MCNN comparison is then repeated for HIVE-COTE. module-validation-hesca-rise informs hive-vs-flat-cote-ucr85: HESCA and RISE results justify their selection as the shapelet and spectral modules used in the main comparison. simulated-datasets confirms hive-vs-flat-cote-ucr85: HIVE-COTE > Flat-COTE is reproduced on 1,000 simulated datasets with known generating mechanism, though with module-level exceptions. case-studies extends hive-vs-flat-cote-ucr85: Three new real problems outside UCR/UEA; HIVE-COTE beats or ties Flat-COTE on all but is beaten by a single module on two. module-validation-hesca-rise comparedWith case-studies: The Vowel and Epilepsy case studies are where RISE alone outperforms the full collective, revisiting the module-level claims. ISS · open questions and untried branches this path leaves behind QUE · positive Is Flat-COTE more accurate than CNNs for time series classification, and can a hierarchical modular collective (HIVE- COTE) be significantly more accurate than Flat-COTE? Is Flat-COTE more accurate than CNNs for time series classification, and can a hierarchical modular collective (HIVE-COTE) be significantly more accurate than Flat-COTE? HYP HIVE-COTE, a hierarchical probabilistic- voting collective over five representations, is significantly more accurate than Flat-COTE and all other known TSC algorithms on the UCR/UEA datasets. HIVE-COTE, a hierarchical probabilistic-voting collective over five representations, is significantly more accurate than Flat-COTE and all other known TSC algorithms on the UCR/UEA datasets. EXP · positive Flat-COTE compared with a benchmark CNN (own Theano implementation, 85 UCR/UEA datasets, 100 resamples) and with published MCNN results (Cui et al. 2016… Flat-COTE compared with a benchmark CNN (own Theano implementation, 85 UCR/UEA datasets, 100 resamples) and with published MCNN results (Cui et al. 2016, 44 datasets, single split) RES · positive Flat-COTE significantly outperforms the benchmark CNN over 85 UCR/UEA datasets, while the CNN's average rank is not… Flat-COTE significantly outperforms the benchmark CNN over 85 UCR/UEA datasets, while the CNN's average rank is not significantly different from DTW 1-NN. RES · positive On the 44 UCR datasets with published MCNN results, Flat-COTE wins 28, MCNN 14, tie 2; mean accuracy 88.6% vs 86.5%… On the 44 UCR datasets with published MCNN results, Flat-COTE wins 28, MCNN 14, tie 2; mean accuracy 88.6% vs 86.5%; significant by binomial and Wilcoxon signed-rank tests. RES · positive On the same 44 datasets (default splits), HIVE-COTE wins 30, MCNN 11, tie 3; the difference is reported as… On the same 44 datasets (default splits), HIVE-COTE wins 30, MCNN 11, tie 3; the difference is reported as significant. EXP · positive HIVE-COTE vs Flat-COTE and 7 leading TSC algorithms over 100 seeded resamples of all 85 UCR/UEA datasets; pairwise Wilcoxon signed-rank tests with Holm… HIVE-COTE vs Flat-COTE and 7 leading TSC algorithms over 100 seeded resamples of all 85 UCR/UEA datasets; pairwise Wilcoxon signed-rank tests with Holm correction (CD diagram) RES · positive HIVE-COTE is significantly more accurate than Flat-COTE and all 7 others over 100 resamples of 85 datasets: mean accuracy… HIVE-COTE is significantly more accurate than Flat-COTE and all 7 others over 100 resamples of 85 datasets: mean accuracy 86.92% vs 85.79%, mean rank 1.61 vs 2.84, 69/85 head-to-head. RES · partial Flat-COTE stays ahead of HIVE-COTE on individual datasets, e.g. Beef 76.4% vs 72.27%, M.PhalanxAgeGroup 72.23% vs… Flat-COTE stays ahead of HIVE-COTE on individual datasets, e.g. Beef 76.4% vs 72.27%, M.PhalanxAgeGroup 72.23% vs 70.49%, SonyAIBORobot2 95.98% vs 94.54%, all 100-resample means. EXP · positive Validation of the two new modules: HESCA vs its 8 constituents (72 UCI datasets, 100 jackknife samples; 85 UCR shapelet- transformed) and RISE vs spectral HESCA… Validation of the two new modules: HESCA vs its 8 constituents (72 UCI datasets, 100 jackknife samples; 85 UCR shapelet-transformed) and RISE vs spectral HESCA; complexity analysis RES · partial On 72 UCI datasets (100 jackknife samples, 30% train) HESCA is significantly more accurate than all… On 72 UCI datasets (100 jackknife samples, 30% train) HESCA is significantly more accurate than all constituents except rotation forest; kept for its smaller train-CV/test gap (0.6106% vs 0.8940%). RES · positive RISE is significantly more accurate than PS-, ACF- and PSACF-HESCA over 100 resamples of 85 UCR/UEA datasets, and… RISE is significantly more accurate than PS-, ACF- and PSACF-HESCA over 100 resamples of 85 UCR/UEA datasets, and combined ACF+PS features beat ACF-only (the 2016 version) or PS-only RISE. RES · inconclusive HIVE-COTE has the same training time complexity as Flat-COTE, O(n^2 m^4), bounded by ST-HESCA shapelet extraction… HIVE-COTE has the same training time complexity as Flat-COTE, O(n^2 m^4), bounded by ST-HESCA shapelet extraction; no wall-clock runtimes are reported. EXP · partial HIVE-COTE and 9 others on 1,000 simulated two-class datasets: 5 simulators (elastic, interval, shapelet, dictionary, spectral) x 200 trials… HIVE-COTE and 9 others on 1,000 simulated two-class datasets: 5 simulators (elastic, interval, shapelet, dictionary, spectral) x 200 trials; Wilcoxon sign-rank, alpha 0.005 RES · positive Over all 1,000 simulated datasets HIVE- COTE is significantly more accurate than Flat-COTE and the other 8 classifiers… Over all 1,000 simulated datasets HIVE-COTE is significantly more accurate than Flat-COTE and the other 8 classifiers (pairwise CD diagram, Figure 18). RES · partial HIVE-COTE is significantly worse than the best on interval (HESCA mean rank 1.65 vs 3.06) and spectral (RISE 1.42 v… HIVE-COTE is significantly worse than the best on interval (HESCA mean rank 1.65 vs 3.06) and spectral (RISE 1.42 vs 2.91) simulations; TSF and RISE unexpectedly rank 7th and 9th on interval data. EXP · partial Three new case studies, 10 classifiers: EthanolLevel (leave-one-bottle-out CV, 4 classes), Epilepsy (leave-one-person- out, 275 instances), Vowel (100… Three new case studies, 10 classifiers: EthanolLevel (leave-one-bottle-out CV, 4 classes), Epilepsy (leave-one-person-out, 275 instances), Vowel (100 resamples, 5 classes) RES · partial EthanolLevel (leave-one-bottle-out): ST- HESCA 84.88% beats HIVE-COTE 84.37%; HIVE-COTE is over 2% above Flat-COTE… EthanolLevel (leave-one-bottle-out): ST-HESCA 84.88% beats HIVE-COTE 84.37%; HIVE-COTE is over 2% above Flat-COTE 82.29%; EE 26.59% and DTW 26.41% are at chance on 4 classes. RES · partial Vowel (100 resamples): RISE 94.93% is best, HIVE-COTE 93.26% second and 3% above Flat-COTE 90.26%, despite its TSF… Vowel (100 resamples): RISE 94.93% is best, HIVE-COTE 93.26% second and 3% above Flat-COTE 90.26%, despite its TSF module scoring 33.64%; PS-HESCA 77.4% and ACF-HESCA 68.9%. ISS · next-step O(n^2 m^4) complexity may be prohibitive for real-time use on low-powered hardware; cutting runtime without losing accuracy, and fair wall-clock… O(n^2 m^4) complexity may be prohibitive for real-time use on low-powered hardware; cutting runtime without losing accuracy, and fair wall-clock comparison, are left open. ISS · untried HESCA constituents and all internal parameters (except 1-NN) are unoptimised; the number of RISE intervals and alternative feature… HESCA constituents and all internal parameters (except 1-NN) are unoptimised; the number of RISE intervals and alternative feature combinations beyond ACF+PS are untried. ISS · open-question HIVE-COTE could not compensate for confounding modules on spectral simulations; alternative fusion strategies (exponential voting, per-… HIVE-COTE could not compensate for confounding modules on spectral simulations; alternative fusion strategies (exponential voting, per-class weighting) are untested. ISS · open-question MCNN significantly beats DTW 1-NN on 44 datasets, so deep learning for TSC warrants further investigation; only one benchmark CNN and one published CNN wer… MCNN significantly beats DTW 1-NN on 44 datasets, so deep learning for TSC warrants further investigation; only one benchmark CNN and one published CNN were compared.
  • supports positive finding
  • opposes a null, worse or failed result against a control or tuned baseline, with a reported test, interval or variance to show it is real
  • informs bears on the question without deciding the hypothesis
  • thin grey a relation between two experiments
Nodes, in reading order. Sources: Lines, Taylor & Bagnall 2018, 10.1145/3182382; version of record from the ACM Digital Library, CC BY 4.0, read in full on 19 October 2026.
NodeTextTypeOutcomeEdge
EXPFlat-COTE compared with a benchmark CNN (own Theano implementation, 85 UCR/UEA datasets, 100 resamples) and with published MCNN results (Cui et al. 2016, 44 datasets, single split)
Flat-COTE is significantly more accurate than both CNNs, confirming it as the baseline to beat; MCNN still significantly beats DTW 1-NN.
benchmark comparisonpositive
RESFlat-COTE significantly outperforms the benchmark CNN over 85 UCR/UEA datasets, while the CNN's average rank is not significantly different from DTW 1-NN.
average rank over 85 UCR/UEA datasets (100 resamples); Flat-COTE significantly better than CNN; CNN vs DTW 1-NN not significantly different; CNN hyper-parameters chosen by minimising training error over learning rate (0.1, 0.01, 0.001), filter size (0.05, 0.1, 0.2), pooling size (2, 3, 5), epochs (50, 100, 200); no accuracy values given in the text
Section 8.1, Figure 13 · “Flat-COTE significantly outperforms the CNN on the 85 UCR/UEA datasets, while the average rank of CNN is not significantly different to DTW.”
positive
informative
informs HYP
RESOn the 44 UCR datasets with published MCNN results, Flat-COTE wins 28, MCNN 14, tie 2; mean accuracy 88.6% vs 86.5%; significant by binomial and Wilcoxon signed-rank tests.
wins/losses/ties = 28/14/2 over 44 datasets (default train/test split, MCNN numbers as published by Cui et al. 2016); average test accuracy Flat-COTE 88.6%, MCNN 86.5% (+2.1% in favour of Flat-COTE); significant by binomial test and Wilcoxon signed-rank test
Section 8.1, Figure 14 · “Flat-COTE wins on 28 datasets, MCNN on 14, and they tie on 2.”
positive
informative
informs HYP
RESOn the same 44 datasets (default splits), HIVE-COTE wins 30, MCNN 11, tie 3; the difference is reported as significant.
wins/losses/ties = 30/11/3 over 44 UCR datasets, default train/test split, MCNN numbers as published; test used not named in this passage (binomial and Wilcoxon signed-rank were used for the Flat-COTE comparison)
Section 8.2, Figure 16 · “HIVE-COTE wins on 30, MCNN on 11, and they tie on 3.”
positive
informative
supports HYP
EXPHIVE-COTE vs Flat-COTE and 7 leading TSC algorithms over 100 seeded resamples of all 85 UCR/UEA datasets; pairwise Wilcoxon signed-rank tests with Holm correction (CD diagram)
HIVE-COTE is significantly more accurate than Flat-COTE and every other algorithm, though Flat-COTE remains ahead on 15 individual datasets.
benchmark comparisonpositive
RESHIVE-COTE is significantly more accurate than Flat-COTE and all 7 others over 100 resamples of 85 datasets: mean accuracy 86.92% vs 85.79%, mean rank 1.61 vs 2.84, 69/85 head-to-head.
average accuracy over 100 resamples x 85 UCR/UEA datasets: HIVE-COTE 86.92, Flat-COTE 85.79, ST-HESCA 83.80, BOSS 83.35, EE 81.19 (%); average rank HIVE-COTE 1.61, Flat-COTE 2.84, ST-HESCA 4.16; HIVE-COTE wins on 45/85 datasets, ranked top 3 on 83, beats Flat-COTE on 69/85; significance via pairwise Wilcoxon signed-rank tests with Holm correction (Figure 15); no CI given
Section 8.2, Tables 5-6, Figure 15 · “HIVE-COTE is significantly more accurate than all alternatives, including Flat-COTE.”
positive
informative
supports HYP
RESFlat-COTE stays ahead of HIVE-COTE on individual datasets, e.g. Beef 76.4% vs 72.27%, M.PhalanxAgeGroup 72.23% vs 70.49%, SonyAIBORobot2 95.98% vs 94.54%, all 100-resample means.
100-resample mean accuracy (%): Beef Flat-COTE 76.4, HIVE-COTE 72.27; M.PhalanxAgeGroup 72.23 vs 70.49; M.PhalanxTW 58.69 vs 57.12; SonyAIBORobot2 95.98 vs 94.54; SonyAIBORobot1 89.91 vs 88.68; ChlorineConcentration 73.56 vs 72.51; no per-dataset variance or test reported
Section 8.2, Tables 5-6 · “beats Flat-COTE on 69/85 problems in a head-to-head comparison.”
partial
informative
informs HYP
EXPValidation of the two new modules: HESCA vs its 8 constituents (72 UCI datasets, 100 jackknife samples; 85 UCR shapelet-transformed) and RISE vs spectral HESCA; complexity analysis
RISE is significantly better than existing spectral approaches; HESCA is not significantly more accurate than rotation forest but gives better-calibrated training estimates; runtime is not measured.
ablation / component validationpositive
RESOn 72 UCI datasets (100 jackknife samples, 30% train) HESCA is significantly more accurate than all constituents except rotation forest; kept for its smaller train-CV/test gap (0.6106% vs 0.8940%).
72 UCI datasets, 100 jackknife samples per dataset, 30% train / 70% test; HESCA significantly more accurate than 7 of 8 constituents, not significantly different from RotF (pairwise Wilcoxon signed-rank, Holm correction); mean train-CV/test accuracy difference HESCA 0.6106% (std error 0.2680), RotF 0.8940% (std error 0.3208), difference significant by F-tests at 5%; authors call the beneficial effects small
Section 5.1-5.2, Figure 7, Table 2 · “HESCA is significantly more accurate than all constituents over the 72 datasets, with the exception of rotation forest (RotF).”
partial
informative
informs HYP
RESRISE is significantly more accurate than PS-, ACF- and PSACF-HESCA over 100 resamples of 85 UCR/UEA datasets, and combined ACF+PS features beat ACF-only (the 2016 version) or PS-only RISE.
100 resamples x 85 UCR/UEA datasets; pairwise CD diagrams (Figures 10, 11); RISE significantly more accurate than HESCA with any spectral feature set; RISE(ACF+PS) significantly more accurate than RISE(ACF) and RISE(PS); on simulated AR data (80 series, length 100, 100 independent runs) no significant difference vs spectral-HESCA on whole-series problem, significantly better when features are embedded in a noisy random interval (rank-based pairwise tests); no numeric accuracies in text
Section 6.1, Figures 9-11; Section 9 · “a novel RISE that we demonstrate is significantly more accurate than existing spectral approaches”
positive
informative
informs HYP
RESHIVE-COTE has the same training time complexity as Flat-COTE, O(n^2 m^4), bounded by ST-HESCA shapelet extraction; no wall-clock runtimes are reported.
training time complexity O(n^2 m^4) for both collectives (Table 4: EE O(n^2 m^2), ST-HESCA O(n^2 m^4), RISE O(k n m^2), TSF O(r m n log n), BOSS O(n m (n - w))); hypothesis of no significant runtime difference stated but not tested; claimed order-of-magnitude speedups from 'internal investigations' with no data shown
Section 7.4, Table 4 · “The time complexity of HIVE-COTE is no different to Flat-COTE.”
inconclusive
informative
informs HYP
EXPHIVE-COTE and 9 others on 1,000 simulated two-class datasets: 5 simulators (elastic, interval, shapelet, dictionary, spectral) x 200 trials; Wilcoxon sign-rank, alpha 0.005
HIVE-COTE beats Flat-COTE and all others when the data source is unknown, but is significantly worse than the best module on interval and spectral data.
simulation studypartial
RESOver all 1,000 simulated datasets HIVE-COTE is significantly more accurate than Flat-COTE and the other 8 classifiers (pairwise CD diagram, Figure 18).
1,000 datasets = 5 simulators x 200 independent trials, random stratified train/test split, 10 classifiers; HIVE-COTE significantly more accurate than Flat-COTE and all others; Wilcoxon sign-rank test with alpha adjusted to 0.005; authors state results identical with sign test, paired t-test and binomial test; accuracy boxplot in Figure 19 (values not in text)
Section 8.3, Figures 18-19 · “HIVE-COTE is significantly more accurate than Flat-COTE on simulated problems when we do not know the source of the data.”
positive
informative
supports HYP
RESHIVE-COTE is significantly worse than the best on interval (HESCA mean rank 1.65 vs 3.06) and spectral (RISE 1.42 vs 2.91) simulations; TSF and RISE unexpectedly rank 7th and 9th on interval data.
mean ranks over 200 trials per simulator (Table 7): interval HESCA 1.65 (1st), HIVE-COTE 3.06 (2nd), Flat-COTE 3.5, TSF 6.26 (7th), RISE 8.25 (9th); spectral RISE 1.42 (1st), HIVE-COTE 2.91 (2nd), Flat-COTE 2.99 (4th); on elastic, shapelet, dictionary HIVE-COTE is best or not significantly worse than best; Wilcoxon sign-rank alpha 0.005
Section 8.3, Table 7 · “The two cases where it is significantly worst than the best are interval and spectral simulators.”
partial
informative
informs HYP
EXPThree new case studies, 10 classifiers: EthanolLevel (leave-one-bottle-out CV, 4 classes), Epilepsy (leave-one-person-out, 275 instances), Vowel (100 resamples, 5 classes)
HIVE-COTE beats Flat-COTE on all three (ties on Epilepsy at 99.27%) but is marginally beaten by one of its own modules on EthanolLevel (ST-HESCA) and Vowel (RISE); no significance tests reported.
case studypartial
RESEthanolLevel (leave-one-bottle-out): ST-HESCA 84.88% beats HIVE-COTE 84.37%; HIVE-COTE is over 2% above Flat-COTE 82.29%; EE 26.59% and DTW 26.41% are at chance on 4 classes.
average accuracy (%) across leave-one-bottle-out folds, Table 8: ST-HESCA 84.88 (stdev 0.096), HIVE-COTE 84.37 (0.084), RotF 84.17 (0.114), HESCA 83.87 (0.112), Flat-COTE 82.29 (0.078), RISE 66.84, TSF 64.45, BOSS 51.98, EE 26.59, DTW 26.41; 20 bottle types, 28 brands, 4 alcohol levels (35, 38, 40, 45%); no significance test reported
Section 8.4.1, Table 8 · “HIVE-COTE itself was over 2% more accurate than Flat-COTE;”
partial
informative
informs HYP
RESVowel (100 resamples): RISE 94.93% is best, HIVE-COTE 93.26% second and 3% above Flat-COTE 90.26%, despite its TSF module scoring 33.64%; PS-HESCA 77.4% and ACF-HESCA 68.9%.
average accuracy (%) over 100 stratified resamples, Table 10: RISE 94.93 (stdev 0.025), HIVE-COTE 93.26 (0.023), ST-HESCA 90.80 (0.032), Flat-COTE 90.26 (0.033), BOSS 80.11, EE 72.14, DTW 68.57, TSF 33.64, HESCA 25.55, RotF 24.23; context runs PS-HESCA 77.4, ACF-HESCA 68.9; 200 utterances (40 per vowel), 50/50 split, audio downsampled 50kHz to 5kHz; no significance test reported
Section 8.4.3, Table 10 · “RISE was the best performing classifier on this problem.”
partial
informative
informs HYP
  • ISS O(n^2 m^4) complexity may be prohibitive for real-time use on low-powered hardware; cutting runtime without losing accuracy, and fair wall-clock comparison, are left open. (next-step · Section 7.4; Section 9)
  • ISS HESCA constituents and all internal parameters (except 1-NN) are unoptimised; the number of RISE intervals and alternative feature combinations beyond ACF+PS are untried. (untried · Section 5.2; Section 9)
  • ISS HIVE-COTE could not compensate for confounding modules on spectral simulations; alternative fusion strategies (exponential voting, per-class weighting) are untested. (open-question · Section 8.3; Section 9)
  • ISS MCNN significantly beats DTW 1-NN on 44 datasets, so deep learning for TSC warrants further investigation; only one benchmark CNN and one published CNN were compared. (open-question · Section 8.1)

Extraction notes: Text appears to be the version of record: ACM TKDD vol. 12 no. 5 article 52, July 2018, received April 2017, revised December 2017, accepted January 2018, CC BY 4.0; some words lack inter-word spaces from PDF extraction. INFERRED: the significance test behind Figures 13 and 15 is not restated in Section 8; Section 5.1 says the pairwise Wilcoxon signed-rank with Holm correction CD method is used 'throughout the remainder of this paper', so I attributed that test to the 85-dataset comparison. The MCNN comparisons (findings flat-cote-beats-mcnn-44, hive-cote-beats-mcnn-44) use numbers copied from Cui et al. (2016) on a single default train/test split for 44 datasets; the authors did not reproduce MCNN, so these are not resample-level comparisons like the rest; the test for the HIVE-COTE vs MCNN comparison is not named (only 'significant'). The benchmark CNN was the authors' own implementation with a small hyper-parameter grid; no accuracy values are given for it, only ranks in Figure 13 (not readable in text). MY COUNT: from Tables 5-6, Flat-COTE exceeds HIVE-COTE on 15 datasets and they tie on Plane, consistent with the stated 69/85; the examples in finding flat-cote-ahead-on-some-datasets are my selection of the larger gaps. Case studies: Table 8 labels stdev as '(%)' but values such as 0.084 look like proportions; Tables 9-10 give stdev with no unit; no significance tests are reported for any case study, so those findings are informs/partial, not supports. Section 8.3 defers simulator details and fuller results to 'Bagnall et al. (2017)', but the reference list has a 2016 UEA technical report on simulated data experiments; likely a citation mismatch, and Table 7 is titled 'Exeriments' (sic). The interval simulator is self-described as poorly designed ('essentially just simulating a standard classification problem with a large number of redundant features'); not listed as an issue only because of the four-issue cap. Runtime: no wall-clock measurements anywhere; the 'at least an order of magnitude' speedup is asserted from internal investigations without data. Quotes are verbatim except that words hyphenated across PDF line breaks were rejoined ('algo-rithms', 'signif-icantly'); 'worst' in the simulation quote is as printed. The hypothesis in Section 8.3 that HIVE-COTE would be not significantly worse than the best module on every data type was partially refuted (interval, spectral); recorded as a finding rather than as the main hypothesis, which I took from the abstract.

TIMESAFE: PTP spoofing and replay attacks on the Open RAN fronthaul and an ML monitor (ACM TOPS, 2025)

Security · ACM Trans. Priv. Secur. 29(1), 2025

A negative result for a security assumption, then a defence: timing attacks on the Open RAN fronthaul take a base station down, and a monitor detects them.

Read left to right. The question (QUE) is addressed by 5 experiments (EXP), each producing results (RES), and each result bears on the hypothesis (HYP). 3 support it, 3 oppose it, 6 inform it. Issues (ISS) hang below: what the paper leaves open.

HYP, in the authors’ words (1 Introduction, Motivation and Scope): “While WG11 acknowledges that attacks on the S-plane can have a high impact, they consider the likelihood low due to the perceived sophistication required by an attacker”

Discourse graph of TIMESAFE: PTP spoofing and replay attacks on the Open RAN fronthaul and an ML monitor (ACM TOPS, 2025) que addresses exp-production-spoofing-attack que addresses exp-digital-twin-attack-impact que addresses exp-offline-detector-comparison que addresses exp-production-trace-detection que addresses exp-reshaped-attack-resilience exp-production-spoofing-attack produces f-prod-spoof-master-port f-prod-spoof-master-port opposes hyp exp-production-spoofing-attack produces f-prod-spoof-dynamic-port-crash f-prod-spoof-dynamic-port-crash opposes hyp exp-production-spoofing-attack produces f-prod-switch-config-blocks-replay f-prod-switch-config-blocks-replay informs hyp exp-digital-twin-attack-impact produces f-twin-spoofing-drift f-twin-spoofing-drift informs hyp exp-digital-twin-attack-impact produces f-twin-replay-delay f-twin-replay-delay opposes hyp exp-offline-detector-comparison produces f-heuristic-baseline-fails f-heuristic-baseline-fails informs hyp exp-offline-detector-comparison produces f-transformer-cnn-offline f-transformer-cnn-offline supports hyp exp-offline-detector-comparison produces f-untrained-dos-attack f-untrained-dos-attack informs hyp exp-production-trace-detection produces f-transformer-production f-transformer-production supports hyp exp-production-trace-detection produces f-cnn-production-degraded f-cnn-production-degraded informs hyp exp-reshaped-attack-resilience produces f-transformer-reshaped f-transformer-reshaped supports hyp exp-reshaped-attack-resilience produces f-cnn-reshaped-fails f-cnn-reshaped-fails informs hyp exp-production-spoofing-attack extends exp-digital-twin-attack-impact: The twin replays production .pcap traces and runs the replay attack that switch configuration blocked on the production network. exp-digital-twin-attack-impact informs exp-offline-detector-comparison: The 32 twin runs, labelled per packet by attacker MAC and attack window, are the training, validation and test data for all detectors. exp-offline-detector-comparison informs exp-production-trace-detection: The two best offline models (CNN and Transformer) were carried forward to the production trace. exp-production-spoofing-attack informs exp-production-trace-detection: The detection trace is the .pcap captured during the Fig. 5 dynamic-port spoofing attack. exp-production-trace-detection confirms exp-reshaped-attack-resilience: Both tests show the Transformer generalising and the CNN failing to; the reshaped-attack test repeats the CNN's generalisation failure on a different shift. ISS · open questions and untried branches this path leaves behind QUE · refuted Can a low-sophistication attacker on the Open RAN fronthaul disrupt PTP synchronisation of a production gNB, and can a DU-side ML monitor detect such attacks? Can a low-sophistication attacker on the Open RAN fronthaul disrupt PTP synchronisation of a production gNB, and can a DU-side ML monitor detect such attacks? HYP WG11 assumption: S-plane PTP attacks are low-likelihood because they need a sophisticated attacker, so a production Open RAN gNB's synchronisation is not readily disrupted. WG11 assumption: S-plane PTP attacks are low-likelihood because they need a sophisticated attacker, so a production Open RAN gNB's synchronisation is not readily disrupted. EXP · refuted Spoofing attack (forged Announce messages) from one of eight DUs on a production-ready NVIDIA ARC / OAI private 5G network, LLS-C3, Dell switch… Spoofing attack (forged Announce messages) from one of eight DUs on a production-ready NVIDIA ARC / OAI private 5G network, LLS-C3, Dell switch, Qulsar grandmaster, one UE RES · refuted With the attacker's switch port in PTP master role, throughput fell 50% about 380 s after attack start, then to 0 wit… With the attacker's switch port in PTP master role, throughput fell 50% about 380 s after attack start, then to 0 with UE disconnect; the DU resynchronised when the attack stopped. RES · refuted With all switch ports PTP-dynamic, the RU crashed approximately 2 seconds after the attack began, the 5G cell dropped… With all switch ports PTP-dynamic, the RU crashed approximately 2 seconds after the attack began, the 5G cell dropped, and the RU required a manual reboot. RES · negative-no-effect A properly configured switch (master- only or slave-only PTP port roles, duplicate-MAC blocking) stopped… A properly configured switch (master-only or slave-only PTP port roles, duplicate-MAC blocking) stopped malicious packets reaching other nodes and prevented the replay attack. EXP · refuted Spoofing and replay attacks in an LLS-C2 digital twin (ptp4l over replayed production .pcap traces), cycles 30/30, 40/20, 50/10 s and continuous, 4 traces… Spoofing and replay attacks in an LLS-C2 digital twin (ptp4l over replayed production .pcap traces), cycles 30/30, 40/20, 50/10 s and continuous, 4 traces, 32 tests of 120 to 450 s RES · refuted Under the 50 s attack / 10 s recovery spoofing cycle, the delay spike reported after each attack showed synchronisatio… Under the 50 s attack / 10 s recovery spoofing cycle, the delay spike reported after each attack showed synchronisation drift that can exceed 40,000 ns. RES · refuted Under the 30/30 s replay cycle, computed delay rose from a normal 25 to 45 ns to peaks over 20 million ns; replay was… Under the 30/30 s replay cycle, computed delay rose from a normal 25 to 45 ns to peaks over 20 million ns; replay was more disruptive than spoofing and slower to recover. EXP · positive Offline comparison of a rule-based heuristic and nine ML models on digital- twin PTP traces: 1,000-message chunks, 80/10/10 split, six packet features… Offline comparison of a rule-based heuristic and nine ML models on digital-twin PTP traces: 1,000-message chunks, 80/10/10 split, six packet features, same test traces for all RES · partial The authors' rule-based heuristic detected Announce attacks but reached only 50.95% accuracy and 17.80% recall… The authors' rule-based heuristic detected Announce attacks but reached only 50.95% accuracy and 17.80% recall offline, missing 82.20% of malicious sequences. RES · positive Transformer reached 97.99% accuracy and 98.33% recall and CNN 97.90% and 97.05% against the heuristic's 50.95% and… Transformer reached 97.99% accuracy and 98.33% recall and CNN 97.90% and 97.05% against the heuristic's 50.95% and 17.80%; the other seven ML models ranged from 65.72% to 86.59% accuracy. RES · partial On a new DoS attack (high-rate random or invalid PTP messages) absent from training, the ML model identified over… On a new DoS attack (high-rate random or invalid PTP messages) absent from training, the ML model identified over 66% of malicious traffic while the heuristic failed completely. EXP · positive TIMESAFE pipeline (sliding window, decision every two PTP packets) run on one .pcap trace captured during the production spoofing attack of Fig. 5… TIMESAFE pipeline (sliding window, decision every two PTP packets) run on one .pcap trace captured during the production spoofing attack of Fig. 5; Transformer vs CNN RES · positive The Transformer with two attention heads and slice length 32 exceeded 99% accuracy on the production attack trace… The Transformer with two attention heads and slice length 32 exceeded 99% accuracy on the production attack trace, detecting 95.70% of malicious sequences with 1.00% false positives. RES · negative-not-replicated The CNN's offline advantage did not transfer to the production trace: it detected only 33.25% of malicious… The CNN's offline advantage did not transfer to the production trace: it detected only 33.25% of malicious sequences (66.75% missed) against 97.05% recall offline. EXP · positive Live TIMESAFE in the digital twin against reshaped attacks: attack duration drawn from [10, 30] s and recovery from [40, 60] s, unlike the… Live TIMESAFE in the digital twin against reshaped attacks: attack duration drawn from [10, 30] s and recovery from [40, 60] s, unlike the fixed training cycles; 5-minute tests RES · positive Against reshaped attack timing the Transformer detected 96.99% of malicious sequences with 4.75% false positives… Against reshaped attack timing the Transformer detected 96.99% of malicious sequences with 4.75% false positives, and attacks were detected with one or two malicious packets reaching the DU. RES · negative-not-achievable Against the same reshaped attacks the CNN detected 0.00% of malicious sequences (100.00% missed) while… Against the same reshaped attacks the CNN detected 0.00% of malicious sequences (100.00% missed) while labelling 99.98% of benign traffic correctly. ISS · untried Only LLS-C2 and LLS-C3 were studied; GNSS jamming of LLS-C4 and supply-chain attacks on primary reference clocks are untried; Prong C redundancy is a… Only LLS-C2 and LLS-C3 were studied; GNSS jamming of LLS-C4 and supply-chain attacks on primary reference clocks are untried; Prong C redundancy is a candidate mitigation. ISS · next-step TIMESAFE covers two attacks; packet removal and selective delay manipulation are not tested, and multi-class classification of attack types is… TIMESAFE covers two attacks; packet removal and selective delay manipulation are not tested, and multi-class classification of attack types is proposed as a next step. ISS · next-step Loss weights were left at one; adaptive threshold tuning or online re-weighting of the false-positive/false-negative trade-off is left to future work. Loss weights were left at one; adaptive threshold tuning or online re-weighting of the false-positive/false-negative trade-off is left to future work. ISS · open-question Whether the RU crash and manual-reboot requirement after the dynamic-port spoofing attack is specific to the Foxconn RU is left open by the authors. Whether the RU crash and manual-reboot requirement after the dynamic-port spoofing attack is specific to the Foxconn RU is left open by the authors.
  • supports positive finding
  • opposes a null, worse or failed result against a control or tuned baseline, with a reported test, interval or variance to show it is real
  • informs bears on the question without deciding the hypothesis
  • thin grey a relation between two experiments
Nodes, in reading order. Sources: Groen, DiValerio, Karim, Villa, Zhang, Bonati, Polese, D’Oro, Melodia, Bertino, Cuomo & Chowdhury 2025, 10.1145/3775060; version of record from the ACM Digital Library, CC BY 4.0, read in full on 19 October 2026.
NodeTextTypeOutcomeEdge
EXPSpoofing attack (forged Announce messages) from one of eight DUs on a production-ready NVIDIA ARC / OAI private 5G network, LLS-C3, Dell switch, Qulsar grandmaster, one UE
A simple Announce-spoofing attack caused a complete gNB outage, within 2 seconds when switch ports were PTP-dynamic, and the RU needed a manual reboot.
attack demonstration on production-ready networkrefuted
RESWith the attacker's switch port in PTP master role, throughput fell 50% about 380 s after attack start, then to 0 with UE disconnect; the DU resynchronised when the attack stopped.
downlink iPerf ~300 Mbps before attack; sudden 50% drop about 380 seconds after attack start (Fig. 4 caption: 50% drop at ~440 s, 75% by ~510 s, crash ~580 s with attack at ~60 s); throughput to 0, UE disconnects; n = 1 run, no variance
6.1 Production-ready Network Impact, Fig. 4 · “About 380 seconds after the beginning of the attack, there is a sudden 50% drop in throughput.”
refuted
informative
opposes HYP
RESWith all switch ports PTP-dynamic, the RU crashed approximately 2 seconds after the attack began, the 5G cell dropped, and the RU required a manual reboot.
RU crash approximately 2 seconds after attack start; throughput ~350 Mbps before attack; 5G cell drops, UE loses connection; RU required manual reboot to regain functionality; n = 1 run, no variance
6.1 Production-ready Network Impact, Fig. 5 · “Approximately 2 seconds after the attack begins, the RU crashes, stopping its operations, causing the 5G cell to drop”
refuted
informative
opposes HYP
RESA properly configured switch (master-only or slave-only PTP port roles, duplicate-MAC blocking) stopped malicious packets reaching other nodes and prevented the replay attack.
no number reported; malicious packets not received by other nodes, verified by Wireshark captures on the malicious machine and other nodes; replay attack prevented under correct switch configuration
6.1 Production-ready Network Impact · “While a properly configured switch prevented our replay attack, assuming correct configurations is risky”
negative-no-effect
informative
informs HYP
EXPSpoofing and replay attacks in an LLS-C2 digital twin (ptp4l over replayed production .pcap traces), cycles 30/30, 40/20, 50/10 s and continuous, 4 traces, 32 tests of 120 to 450 s
Both attacks caused large synchronisation drift on the RU; replay was more disruptive than spoofing and took longer to recover from.
attack impact measurement on emulated targetrefuted
RESUnder the 50 s attack / 10 s recovery spoofing cycle, the delay spike reported after each attack showed synchronisation drift that can exceed 40,000 ns.
synchronisation drift can exceed 40,000 ns after a 50-second spoofing period; drift reported on recovery because no Sync messages flow during the attack; severity depends on each device's internal clock and attack length; 4 background traces; no variance given
6.2 Digital Twin Network Impact, Fig. 6 · “the announce attack (dark red) shows synchronization drift can exceed 40,000 ns.”
refuted
informative
informs HYP
RESUnder the 30/30 s replay cycle, computed delay rose from a normal 25 to 45 ns to peaks over 20 million ns; replay was more disruptive than spoofing and slower to recover.
normal delay 25 to 45 nanoseconds; replay attack peaks over 20 million nanoseconds (Fig. 7); Appendix A.1: reported delays over 8,000 times greater than the actual observed delay; 4 background traces; no variance given
6.2 Digital Twin Network Impact, Fig. 7; Appendix A.1 · “during the Replay attack, these values spike by several orders of magnitude, peaking at over 20 million nanoseconds”
refuted
informative
opposes HYP
EXPOffline comparison of a rule-based heuristic and nine ML models on digital-twin PTP traces: 1,000-message chunks, 80/10/10 split, six packet features, same test traces for all
Every ML model beat the heuristic; the Transformer (97.99% accuracy, 98.33% recall) and CNN (97.90%, 97.05%) were far ahead and were selected for deployment.
benchmark comparisonpositive
RESThe authors' rule-based heuristic detected Announce attacks but reached only 50.95% accuracy and 17.80% recall offline, missing 82.20% of malicious sequences.
Heuristic accuracy = 50.95%, recall = 17.80% (Table 3); Fig. 8 confusion matrix: 82.20% of malicious labelled benign, 0.53% of benign labelled malicious; legitimate packets during an attack reset the heuristic; single split, no variance
7.1 Heuristic Detection Results, Fig. 8, Table 3 · “while the heuristic effectively detects Announce attacks, it struggles with overall accuracy”
partial
informative
informs HYP
RESTransformer reached 97.99% accuracy and 98.33% recall and CNN 97.90% and 97.05% against the heuristic's 50.95% and 17.80%; the other seven ML models ranged from 65.72% to 86.59% accuracy.
Transformer accuracy = 97.99%, recall = 98.33%; CNN 97.90% / 97.05%; heuristic 50.95% / 17.80%; Naive Bayes 65.72% / 83.26%; Gradient Boosting 86.59% / 58.75% (Table 3); Fig. 9: CNN 0.58% FP, 4.31% FN; Transformer 2.51% FP, 1.67% FN; single split, no seeds, CI or significance test
8.1 ML Model Selection, Table 3, Fig. 9 · “The CNN and Transformer models achieve significantly higher performance than other methods.”
positive
informative
supports HYP
RESOn a new DoS attack (high-rate random or invalid PTP messages) absent from training, the ML model identified over 66% of malicious traffic while the heuristic failed completely.
over 66% of malicious traffic correctly identified by the ML model; heuristic model failed completely; the DoS attack did not disrupt PTP timing; which ML model, denominator and variance not stated
7 Need for ML Based Detection, Flexibility · “correctly identified over 66% of the malicious traffic, whereas the heuristic model failed completely”
partial
informative
informs HYP
EXPTIMESAFE pipeline (sliding window, decision every two PTP packets) run on one .pcap trace captured during the production spoofing attack of Fig. 5; Transformer vs CNN
The Transformer (two heads, slice length 32) exceeded 99% accuracy on the production trace while the CNN trained on the same twin data detected only 33.25% of malicious sequences.
detector generalisation test on real tracepositive
RESThe Transformer with two attention heads and slice length 32 exceeded 99% accuracy on the production attack trace, detecting 95.70% of malicious sequences with 1.00% false positives.
accuracy exceeding 99%; Fig. 12(a): benign 99.00% correct / 1.00% false positive, malicious 95.70% detected / 4.30% missed; one .pcap trace, one attack; no variance or interval reported
9.1 Production-ready Detection Accuracy, Fig. 12(a) · “the transformer model with two attention heads and a slice length of 32 significantly outperformed other transformer configurations, achieving an accuracy exceeding 99%”
positive
informative
supports HYP
RESThe CNN's offline advantage did not transfer to the production trace: it detected only 33.25% of malicious sequences (66.75% missed) against 97.05% recall offline.
Fig. 12(b): benign 99.97% correct / 0.03% false positive, malicious 33.25% detected / 66.75% missed; same trace as Transformer; offline recall had been 97.05% (Table 3); no variance
9.1 Production-ready Detection Accuracy, Fig. 12(b) · “the performance of the CNN model was substantially degraded when applied to the new environment”
negative-not-replicated
informative
informs HYP
EXPLive TIMESAFE in the digital twin against reshaped attacks: attack duration drawn from [10, 30] s and recovery from [40, 60] s, unlike the fixed training cycles; 5-minute tests
The Transformer kept 96.99% detection under unseen attack timing and detected attacks after one or two malicious packets; the CNN detected 0.00%.
robustness test to distribution shiftpositive
RESAgainst reshaped attack timing the Transformer detected 96.99% of malicious sequences with 4.75% false positives, and attacks were detected with one or two malicious packets reaching the DU.
Fig. 13(a): benign 95.25% correct / 4.75% false positive, malicious 96.99% detected / 3.01% missed; attack duration random in [10, 30] s, recovery in [40, 60] s; 5-minute tests, number of tests not stated; no variance
9.2 Digital Twin Detection Accuracy, Fig. 13(a) · “The transformer demonstrated excellent resilience against the reshaped attack, while the CNN completely failed to detect it.”
positive
informative
supports HYP
RESAgainst the same reshaped attacks the CNN detected 0.00% of malicious sequences (100.00% missed) while labelling 99.98% of benign traffic correctly.
Fig. 13(b): benign 99.98% correct / 0.02% false positive, malicious 0.00% detected / 100.00% missed; same tests as Transformer; no variance
9.2 Digital Twin Detection Accuracy, Fig. 13(b) · “The transformer shows resilience to this strategy change, while the CNN fails to generalize.”
negative-not-achievable
informative
informs HYP
  • ISS Only LLS-C2 and LLS-C3 were studied; GNSS jamming of LLS-C4 and supply-chain attacks on primary reference clocks are untried; Prong C redundancy is a candidate mitigation. (untried · 10 Discussion, Attacks in Other Synchronization Topologies)
  • ISS TIMESAFE covers two attacks; packet removal and selective delay manipulation are not tested, and multi-class classification of attack types is proposed as a next step. (next-step · 10 Discussion, Additional Attacks Against PTP)
  • ISS Loss weights were left at one; adaptive threshold tuning or online re-weighting of the false-positive/false-negative trade-off is left to future work. (next-step · 8.2 ML Model Description)
  • ISS Whether the RU crash and manual-reboot requirement after the dynamic-port spoofing attack is specific to the Foxconn RU is left open by the authors. (open-question · 6.1 Production-ready Network Impact)

Extraction notes: Version: the text is the published journal article, ACM Trans. Priv. Sec. vol. 29 no. 1 article 7, December 2025, CC BY 4.0; footer reads 'Received 9 May 2025; revised 9 May 2025; accepted 5 November 2025' (received and revised dates identical, probably a typesetting slip). Hypothesis choice: per the brief's security-paper rule, the hypothesis is the security assumption the attacks test, taken from the authors' own framing of O-RAN WG11's position (likelihood low because of attacker sophistication). The three attack findings with valence 'opposes' and outcomeClass 'refuted' are demonstrated attacks with measured effects on the production network or the emulated twin; 'refuted' is my reading of what a successful attack does to that assumption (the paper's own words are 'high impact'). The twin spoofing-drift finding is 'informs' rather than 'opposes' because it quantifies severity of an attack the production run already decided, and the twin runs without SyncE (Appendix A.2), which the authors flag as a difference from production. The switch-configuration finding (replay blocked) is classed negative-no-effect/informs as an attack condition; that classification is mine. Detector experiments (exp-offline-detector-comparison, exp-production-trace-detection, exp-reshaped-attack-resilience): as the caller asked, their valences are drawn against the detector's claim, quoted from the Introduction: 'our Machine Learning (ML) model can effectively identify malicious PTP attacks with over 97.5% accuracy across diverse environments', not against the WG11 hypothesis; this is a second reference claim living in one graph, so 'supports' on those findings means 'supports the detector claim'. The rule-based baseline was implemented by the authors, so the baseline is reproduced, but NO result anywhere in the paper comes with seeds, repeated runs, confidence intervals or a significance test: Table 3 is one 80/10/10 split, Fig. 12 is one .pcap trace of one attack, Fig. 13 gives no count of tests. Under the strictest reading of the brief's fairness condition the detector 'supports' edges would downgrade to consistent-with/inconclusive; I kept 'supports' because the gap to the reproduced baseline (97.99% vs 50.95% accuracy) is large, and flag the absence of variance in every effect field for the reviewer to decide. CNN failures: the production-trace CNN result is classed negative-not-replicated (its offline 97.05% recall did not transfer), and the reshaped-attack CNN result negative-not-achievable (0.00% detection), both 'informs' because they bear on the CNN, not on the Transformer that carries the claim. Self-inconsistencies in the paper: the abstract and conclusion say 'over 97.5% accuracy', Section 7 says '99% accuracy in a production environment' and Section 9.1 'exceeding 99%', while Fig. 12(a) shows 95.70% of malicious sequences detected (overall accuracy above 99% is plausible only if benign sequences dominate the trace, which the paper does not state); Table 3 names 'Linear Regression' while Appendix A.3 describes 'Logistic Regression'; Section 7.1 says the heuristic was tested 'under the same conditions we use in Section 9.2' (the reshaped-attack twin run) while Table 3 labels its 50.95%/17.80% as the offline dataset, so it is unclear which setting Fig. 8 reports; Section 8.1 says the dataset and pipeline will be open-sourced 'upon acceptance' while the Introduction says they are already released at reference [5]. Figure 4 caption times (50% drop at ~440 s, 75% at ~510 s, crash ~580 s with attack at ~60 s) and the text's 'about 380 seconds after the beginning of the attack' are consistent but I copied both rather than reconciling them. The '66%' DoS finding does not say which ML model was used. Fig. 6 and 7 panel titles name four trace files (run1-12sep-aerial-udpDL, run1-8sep-aerial-increasingDL-withUL, run2-8sep-aerial-increasingDL-noUL, run3-8sep-aerial-maxDLUL), which I take to be the four background traffic traces. Training cost (never exceeded 30 minutes on one A100) and real-time inference on both models are stated without numbers for latency, so not recorded as findings.

ARIoTEDef: self-evolving IoT early-infection detector against white-box evasion (ACM Trans. Internet Things, 2024)

Security · ACM Trans. Internet Things 5(3), 2024

A positive result that starts with a failure: the infection detector is fully evaded by a white-box attack before self-evolution recovers most of its recall.

Read left to right. The question (QUE) is addressed by 5 experiments (EXP), each producing results (RES), and each result bears on the hypothesis (HYP). 5 support it, 0 oppose it, 6 inform it. Issues (ISS) hang below: what the paper leaves open.

HYP, in the authors’ words (Abstract): “Our results show that ARIoTEDef is robust and benefits from multiple rounds of evolution.”

Discourse graph of ARIoTEDef: self-evolving IoT early-infection detector against white-box evasion (ACM Trans. Internet Things, 2024) que addresses exp-regular-setting-clean que addresses exp-pre-evolution-attack-baseline que addresses exp-adversarial-setting-i que addresses exp-adversarial-setting-ii que addresses exp-pgd-at-comparison exp-regular-setting-clean produces f-one-round-f1 f-one-round-f1 supports hyp exp-regular-setting-clean produces f-attention-vs-tagging-baselines f-attention-vs-tagging-baselines supports hyp exp-regular-setting-clean produces f-cross-nids-evolution f-cross-nids-evolution supports hyp exp-pre-evolution-attack-baseline produces f-clean-and-blackbox-baseline f-clean-and-blackbox-baseline informs hyp exp-pre-evolution-attack-baseline produces f-pgd-recall-zero-before-evolution f-pgd-recall-zero-before-evolution informs hyp exp-pre-evolution-attack-baseline produces f-sequence-analyzer-threshold f-sequence-analyzer-threshold informs hyp exp-adversarial-setting-i produces f-recall-after-20-40-80-rounds f-recall-after-20-40-80-rounds supports hyp exp-adversarial-setting-i produces f-clean-set-cost-of-evolution f-clean-set-cost-of-evolution informs hyp exp-adversarial-setting-i produces f-evolution-overhead f-evolution-overhead informs hyp exp-adversarial-setting-ii produces f-setting-ii-small-gain f-setting-ii-small-gain informs hyp exp-pgd-at-comparison produces f-vs-pgd-at f-vs-pgd-at supports hyp exp-pre-evolution-attack-baseline informs exp-adversarial-setting-i: The round-0 detector M0 with 0.00% PGD recall (Table 4) is the starting point of every evolution run in Tables 6 and 7. exp-regular-setting-clean extends exp-adversarial-setting-i: Section 7 redefines the evolution set (Definition 4) and reuses Strategy 1/2 from the regular setting so adversarial samples the detector missed can be relabelled. exp-adversarial-setting-i comparedWith exp-adversarial-setting-ii: Same self-evolution strategy; Setting II uses fresh clean samples and far fewer adversarial samples per round and yields much smaller recall gains (6.67-14.47% vs 64.88-82.18%). exp-adversarial-setting-i informs exp-pgd-at-comparison: The 80-round detector from Setting I is the model compared against PGD-AT. exp-pre-evolution-attack-baseline informs exp-adversarial-setting-ii: Pre-evolved detectors are re-evaluated on same-size adversarial sets (53, 28, 15) and again show 0.00% recall. ISS · open questions and untried branches this path leaves behind QUE · partial Can backtracking from detected action events to relabel and retrain the infection detector make an IoT NIDS detect early infections and resist adversarial evasion? Can backtracking from detected action events to relabel and retrain the infection detector make an IoT NIDS detect early infections and resist adversarial evasion? HYP Self-evolution (attention-based Seq2Seq relabelling plus retraining) makes the infection detector effective on clean attacks and robust to white-box evasion, improving with more rounds. Self-evolution (attention-based Seq2Seq relabelling plus retraining) makes the infection detector effective on clean attacks and robust to white-box evasion, improving with more rounds. EXP · positive Regular setting on Mirai botnet and Log4j datasets: baseline infection detector vs attention-based identification vs one-round evolved… Regular setting on Mirai botnet and Log4j datasets: baseline infection detector vs attention-based identification vs one-round evolved detector; 30 trials per scenario. RES · positive After one evolution round the infection detector's average F1 rose from 0.31 to 0.87 (Strategy 2); Strategy 1 gave F1… After one evolution round the infection detector's average F1 rose from 0.31 to 0.87 (Strategy 2); Strategy 1 gave F1 0.82 / precision 0.77, Strategy 3 F1 0.72 / precision 0.64. RES · positive The attention-based identification algorithm reached F1 0.85 against highest-probability 0.65, episode tree… The attention-based identification algorithm reached F1 0.85 against highest-probability 0.65, episode tree 0.46 and Viterbi 0.20 on the same event sequences. RES · positive On test set 2 the un-evolved LSTM infection detector scored F1 0.14, below HAM (0.19) and SAAE-DNN (0.77); after… On test set 2 the un-evolved LSTM infection detector scored F1 0.14, below HAM (0.19) and SAAE-DNN (0.77); after Strategy 2 evolution LSTM reached 0.92, HAM 0.42 and SAAE-DNN 0.86. EXP · refuted Pre-evolution baseline: LSTM per-step detectors trained 40 epochs on clean Mirai windows, attacked with black-box (Boundary, HopSkipJump) and white-box… Pre-evolution baseline: LSTM per-step detectors trained 40 epochs on clean Mirai windows, attacked with black-box (Boundary, HopSkipJump) and white-box (FGSM, PGD) evasion. RES · positive Baseline infection detector had clean accuracy 94.80% but clean recall only 39.62% (TP 126, FN 192 of 318); Boundar… Baseline infection detector had clean accuracy 94.80% but clean recall only 39.62% (TP 126, FN 192 of 318); Boundary and HopSkipJump black-box attacks left recall unchanged at 39.62%. RES · refuted Under white-box untargeted PGD (eps 1.0, step 0.5, 20 iterations) the pre-evolved infection detector classified all 318… Under white-box untargeted PGD (eps 1.0, step 0.5, 20 iterations) the pre-evolved infection detector classified all 318 adversarial infection samples as benign: TP 0, FN 318, recall 0.00%. RES · partial The sequence analyzer that supplies relabels is itself weak on the clean infection test set: at the chosen 0.01… The sequence analyzer that supplies relabels is itself weak on the clean infection test set: at the chosen 0.01 threshold average precision 63.42%, recall 43.54%, F1 50.89%, FPR 2.58% (4 seeds). EXP · positive Adversarial Setting I: PGD samples from the same 318 clean infection samples against the latest evolved detector each round; 20, 40, 80 rounds; 3 seeds… Adversarial Setting I: PGD samples from the same 318 clean infection samples against the latest evolved detector each round; 20, 40, 80 rounds; 3 seeds; white-box and clean tests. RES · positive Average recall on white-box PGD infection samples rose from 0.00% (round 0) to 64.88% after 20 rounds, 70.96%… Average recall on white-box PGD infection samples rose from 0.00% (round 0) to 64.88% after 20 rounds, 70.96% after 40 and 82.18% after 80; best single seed 95.91% at 80 rounds. RES · partial On the clean test set evolution raised recall (39.62% to 82.18%) and F1 (53.39% to 67.64%) but cut precision from 81.82… On the clean test set evolution raised recall (39.62% to 82.18%) and F1 (53.39% to 67.64%) but cut precision from 81.82% to 57.74% and raised FPR from 0.72% to 4.92% at 80 rounds. RES · positive Each evolution round (40 epochs, 318 adversarial samples) takes about 55s; a per-step detector has 218,753 parameter… Each evolution round (40 epochs, 318 adversarial samples) takes about 55s; a per-step detector has 218,753 parameters (2.6M file), the sequence analyzer 200,705 (2.4M); 0.007s per window. EXP · partial Adversarial Setting II: disjoint clean sub-sets so each attack round uses new samples (53, 28 or 15 adversarial samples per round); 5, 10 and 20 rounds… Adversarial Setting II: disjoint clean sub-sets so each attack round uses new samples (53, 28 or 15 adversarial samples per round); 5, 10 and 20 rounds; 3 seeds. RES · partial With new clean samples each round, average white-box recall rose from 0.00% to only 14.47% (5 rounds, 53… With new clean samples each round, average white-box recall rose from 0.00% to only 14.47% (5 rounds, 53 samples/round), 14.29% (10 rounds, 28/round) and 6.67% (20 rounds, 15/round). EXP · positive 80-round evolved infection detector vs a PGD adversarial training (PGD-AT) detector trained by the authors, on white-box PGD samples and the clean tes… 80-round evolved infection detector vs a PGD adversarial training (PGD-AT) detector trained by the authors, on white-box PGD samples and the clean test set; three experiments. RES · positive The 80-round evolved detector averaged 8.38% higher white-box recall than PGD- AT, plus 27.13% higher precision, 22.11… The 80-round evolved detector averaged 8.38% higher white-box recall than PGD-AT, plus 27.13% higher precision, 22.11% higher F1, 10.39% higher accuracy and 11.82% lower FPR on clean samples. ISS · next-step Add host information (system calls, CPU/memory and resource usage) and more kill-chain steps (lateral movement, obfuscation) beyond the three network… Add host information (system calls, CPU/memory and resource usage) and more kill-chain steps (lateral movement, obfuscation) beyond the three network stages modelled. ISS · open-question Robustness gain depends on how many adversarial samples the attacker sends per round; with few samples the learnable perturbation patterns are ver… Robustness gain depends on how many adversarial samples the attacker sends per round; with few samples the learnable perturbation patterns are very limited (Setting II). ISS · open-question Not every evolution round beats the attacker: samples used for retraining depend on the sequence analyzer's predictions, which average only 43.54%… Not every evolution round beats the attacker: samples used for retraining depend on the sequence analyzer's predictions, which average only 43.54% recall at the chosen threshold. ISS · open-question Class imbalance (3,915 benign vs 318 infection windows) makes the sequence analyzer's score threshold a key sensitivity; 0.01 was found by multiple… Class imbalance (3,915 benign vs 318 infection windows) makes the sequence analyzer's score threshold a key sensitivity; 0.01 was found by multiple tries, not a principled rule.
  • supports positive finding
  • opposes a null, worse or failed result against a control or tuned baseline, with a reported test, interval or variance to show it is real
  • informs bears on the question without deciding the hypothesis
  • thin grey a relation between two experiments
Nodes, in reading order. Sources: Huang, Lee, Kundu, Chen, Mudgerikar, Li & Bertino 2024, 10.1145/3660646; version of record from the ACM Digital Library, CC BY 4.0, read in full on 19 October 2026.
NodeTextTypeOutcomeEdge
EXPRegular setting on Mirai botnet and Log4j datasets: baseline infection detector vs attention-based identification vs one-round evolved detector; 30 trials per scenario.
One round of self-evolution raised the infection detector's average F1 from 0.31 to 0.87, and the attention-based identifier beat three sequence-tagging baselines.
benchmark comparison / ablationpositive
RESAfter one evolution round the infection detector's average F1 rose from 0.31 to 0.87 (Strategy 2); Strategy 1 gave F1 0.82 / precision 0.77, Strategy 3 F1 0.72 / precision 0.64.
average F1 = 0.31 -> 0.87 after one evolution round (Strategy 2, precision 0.82); Strategy 1 F1 0.82, precision 0.77; Strategy 3 F1 0.72, precision 0.64; averaged over 30 trials per scenario, no variance reported
Abstract; Section 6.6, Figure 7 · “Strategy 2 works best (highest F1 score of 0.87) with the highest precision (0.82).”
positive
informative
supports HYP
RESThe attention-based identification algorithm reached F1 0.85 against highest-probability 0.65, episode tree 0.46 and Viterbi 0.20 on the same event sequences.
F1 = 0.85 (Attention) vs 0.65 (highest probability), 0.46 (episode tree), 0.20 (Viterbi); 30 trials per scenario, no variance reported
Section 6.5, Figure 6 · “The performance of the episode tree (0.46) and Viterbi (0.20) is even worse than the highest probability (0.65).”
positive
informative
supports HYP
RESOn test set 2 the un-evolved LSTM infection detector scored F1 0.14, below HAM (0.19) and SAAE-DNN (0.77); after Strategy 2 evolution LSTM reached 0.92, HAM 0.42 and SAAE-DNN 0.86.
F1 on set2: LSTM 0.14 -> 0.92; HAM 0.19 -> 0.42; SAAE-DNN 0.77 -> 0.86 after evolution using set1 results; HAM and SAAE-DNN re-implemented by the authors; no variance reported
Section 6.7, Figure 8 · “However, the F1 score of LSTM becomes the highest (0.92) after being evolved.”
positive
informative
supports HYP
EXPPre-evolution baseline: LSTM per-step detectors trained 40 epochs on clean Mirai windows, attacked with black-box (Boundary, HopSkipJump) and white-box (FGSM, PGD) evasion.
Black-box attacks did not evade the detectors, but white-box untargeted PGD (eps 1.0, step 0.5, 20 iterations) drove the infection detector's recall to 0.00%.
robustness evaluation of the un-evolved detector (attack before the fix)refuted
RESBaseline infection detector had clean accuracy 94.80% but clean recall only 39.62% (TP 126, FN 192 of 318); Boundary and HopSkipJump black-box attacks left recall unchanged at 39.62%.
clean accuracy = 94.80% (infection), 96.48% (reconnaissance), 97.73% (action); infection detector clean TP 126 / FN 192, recall 39.62%; Boundary (eps 1.0, 500,000 iterations, 100,000 queries) and HopSkipJump: TP 126 / FN 192, recall 39.62%, unchanged; single run
Section 3.2, Table 2; Section 8.2 · “such black-box attacks are unable to evade the per-step detectors even with large perturbation budgets, iteration rounds, and query times.”
positive
informative
informs HYP
RESUnder white-box untargeted PGD (eps 1.0, step 0.5, 20 iterations) the pre-evolved infection detector classified all 318 adversarial infection samples as benign: TP 0, FN 318, recall 0.00%.
untargeted PGD eps=1.0, eps_ite=0.5, n_ite=20: infection detector TP 0, FN 318, FNR 100.00%, recall 0.00%; untargeted FGSM eps=1.0 also recall 0.00%; reconnaissance detector under same PGD recall 0.94%; action detector white-box success rate almost 0; single run (Table 4)
Section 8.2, Table 4; Section 8.4.2 · “since all adversarial infection samples are misclassified as benign, resulting in an FNR close to 100 %”
refuted
informative
informs HYP
RESThe sequence analyzer that supplies relabels is itself weak on the clean infection test set: at the chosen 0.01 threshold average precision 63.42%, recall 43.54%, F1 50.89%, FPR 2.58% (4 seeds).
threshold 0.5: average FNR 79.40%, FPR 0.04%, precision 98.10%, recall 20.60%, F1 33.88%; threshold 0.1: F1 42.49%; threshold 0.01: average TP 153, FN 199, TN 3,772, FP 100, precision 63.42%, recall 43.54%, F1 50.89%, accuracy 92.93%; seeds 0-3
Section 8.3, Table 5 · “we found that when the threshold is set to 0.01, an ideal balance can be achieved between precision and recall.”
partial
informative
informs HYP
EXPAdversarial Setting I: PGD samples from the same 318 clean infection samples against the latest evolved detector each round; 20, 40, 80 rounds; 3 seeds; white-box and clean tests.
Average recall on white-box PGD samples rose from 0.00% to 64.88%, 70.96% and 82.18% after 20, 40 and 80 rounds, at the cost of lower precision and higher FPR on the clean test set.
multi-round attack-defence robustness studypositive
RESAverage recall on white-box PGD infection samples rose from 0.00% (round 0) to 64.88% after 20 rounds, 70.96% after 40 and 82.18% after 80; best single seed 95.91% at 80 rounds.
recall = 0.00% (round 0) -> 64.88% (20 rounds; seeds 61.01/62.26/71.38), 70.96% (40 rounds; 72.96/73.27/66.67), 82.18% (80 rounds; 72.01/95.91/78.62); average FNR 35.12%, 29.04%, 17.82%; 318 adversarial samples per round; 3 seeds
Section 8.4.2, Table 6, Figures 9-10 · “After 20 rounds, 40 rounds, and 80 rounds of self-evolution, the average recall of the infection detector increases to 64.88 % , 70.96 % , and 82.18 % , respectively.”
positive
informative
supports HYP
RESOn the clean test set evolution raised recall (39.62% to 82.18%) and F1 (53.39% to 67.64%) but cut precision from 81.82% to 57.74% and raised FPR from 0.72% to 4.92% at 80 rounds.
clean test set (3,915 benign, 318 malicious): round 0 precision 81.82%, recall 39.62%, F1 53.39%, FPR 0.72%, accuracy 94.80%; 20 rounds precision 60.86%, recall 75.58%, F1 66.98%, FPR 3.98%, accuracy 94.49%; 40 rounds precision 53.57%, recall 71.91%, F1 61.04%, FPR 5.24%, accuracy 93.05%; 80 rounds precision 57.74%, recall 82.18%, F1 67.64%, FPR 4.92%, accuracy 94.11%; 3 seeds
Section 8.4.3, Table 7, Figure 11 · “the slight decline in precision is almost negligible compared to the significant increase in recall.”
partial
informative
informs HYP
RESEach evolution round (40 epochs, 318 adversarial samples) takes about 55s; a per-step detector has 218,753 parameters (2.6M file), the sequence analyzer 200,705 (2.4M); 0.007s per window.
per-round evolution time about 55s (40 epochs, 318 adversarial samples); parameters 218,753 per per-step detector, 200,705 sequence analyzer; HDF5 size 2.6M and 2.4M; training epoch 0.75s/1.05s/1.0s for the three detectors, 12.25s for sequence analyzer; inference 0.007s per window, 0.065s per event sequence; max GPU power 115W detectors, 152W sequence analyzer; NVIDIA GeForce P8
Section 8.6, Figure 15 · “Under the default setting of 40 epochs, it takes about 55s for per-round evolution.”
positive
informative
informs HYP
EXPAdversarial Setting II: disjoint clean sub-sets so each attack round uses new samples (53, 28 or 15 adversarial samples per round); 5, 10 and 20 rounds; 3 seeds.
With few, unseen adversarial samples per round the recall gain was small: 0% rose only to 14.47%, 14.29% and 6.67% after 5, 10 and 20 rounds.
multi-round attack-defence robustness study with unseen data per roundpartial
RESWith new clean samples each round, average white-box recall rose from 0.00% to only 14.47% (5 rounds, 53 samples/round), 14.29% (10 rounds, 28/round) and 6.67% (20 rounds, 15/round).
recall = 0.00% (round 0) -> 14.47% (5 rounds; seeds 5.66/32.08/5.66, FNR 85.53%), 14.29% (10 rounds; 21.43/21.43/0.00, FNR 85.71%), 6.67% (20 rounds; 6.67/6.67/6.67, TP 1 of 15 each seed, FNR 93.33%); 3 seeds; pre-evolved detector evaluated on same-size adversarial sets
Section 8.5.2, Table 9, Figures 12-13 · “After 5, 10, and 20 rounds of evolution, the average recall of the infection detector increased to 14.47 % , 14.29 % , and 6.67 % , respectively”
partial
informative
informs HYP
EXP80-round evolved infection detector vs a PGD adversarial training (PGD-AT) detector trained by the authors, on white-box PGD samples and the clean test set; three experiments.
The evolved detector's recall on white-box samples was 8.38% higher than PGD-AT on average, with higher precision, F1 and accuracy and lower FPR on clean samples.
benchmark comparison against a robust-training baselinepositive
RESThe 80-round evolved detector averaged 8.38% higher white-box recall than PGD-AT, plus 27.13% higher precision, 22.11% higher F1, 10.39% higher accuracy and 11.82% lower FPR on clean samples.
white-box recall: evolved (80 rounds) 8.38 % higher than PGD-AT on average over three experiments; clean set: precision 27.13% higher, F1 22.11% higher, accuracy 10.39% higher, FPR 11.82% lower; absolute values only in Figures 16-17, no variance stated in text
Section 8.7, Figures 16-17 · “the recall of the 80-round evolved infection detector on white-box adversarial samples is 8.38 % higher than that of PGD-AT trained detector on average.”
positive
informative
supports HYP
  • ISS Add host information (system calls, CPU/memory and resource usage) and more kill-chain steps (lateral movement, obfuscation) beyond the three network stages modelled. (next-step · Section 9 Conclusion)
  • ISS Robustness gain depends on how many adversarial samples the attacker sends per round; with few samples the learnable perturbation patterns are very limited (Setting II). (open-question · Section 8.5.2)
  • ISS Not every evolution round beats the attacker: samples used for retraining depend on the sequence analyzer's predictions, which average only 43.54% recall at the chosen threshold. (open-question · Sections 8.3 and 8.5.2, Table 5)
  • ISS Class imbalance (3,915 benign vs 318 infection windows) makes the sequence analyzer's score threshold a key sensitivity; 0.01 was found by multiple tries, not a principled rule. (open-question · Section 8.3)

Extraction notes: Version: text is the published ACM Transactions on Internet of Things Vol. 5, No. 3, Article 15 (June 2024) version, received 22 August 2023, revised 2 February 2024, accepted 24 March 2024; the copyright line reads '2023' while the publication date is June 2024. The hypothesis quote is from the abstract; the conclusion states the same claim more fully but spans a hyphenated line break in the text. Reading choices that are mine, not the authors': (1) the question outcomeClass is 'partial' because Setting I strongly supports the claim while Setting II (fresh samples, small batches) gives only 6.67-14.47% recall; the authors present Setting II as showing 'evolution helps to reduce FNs' and do not call it a limitation; a reader could reasonably treat it as opposing the robustness claim for slow or low-volume attackers; (2) the pre-evolution PGD result is classed 'refuted' (the un-evolved detector's robustness) with valence 'informs' because the paper's claim is about the evolved detector; (3) the overhead finding is classed 'positive' only because the authors present it as lightweight; it is a cost measurement with no comparison. Fairness: all baselines (highest probability, Viterbi, episode tree, HAM, SAAE-DNN, PGD-AT) were implemented or trained by the authors; the regular-setting numbers are averages over 30 trials with no variance given; the adversarial-setting tables give per-seed values for 3 seeds (4 seeds for Table 5); the PGD-AT comparison reports only relative differences 'after three experiments' and absolute values appear only in Figures 16-17, which are not in the text. Self-inconsistencies and gaps: the abstract's baseline F1 of 0.31 is not stated anywhere in the body (Figure 7 only); Section 6.7 gives the un-evolved LSTM F1 as 0.14 on a different test set (set2); the round-0 F1 in Table 7 is 53.39% on the Section 8 dataset, so the '0.31 to 0.87' and the '53.39% to 67.64%' improvements are from different datasets and settings; in Section 8.3 the sentence 'the FNR increases but to a limited extent' almost certainly means FPR (Table 5 shows FNR falling and FPR rising as the threshold drops); Table 2 mixes '39.62%' with a percent sign and other recalls without one. Clean-set F1 in Setting I is non-monotonic (66.98% at 20 rounds, 61.04% at 40, 67.64% at 80), which the authors do not discuss. The '8.38 % higher' and similar PGD-AT figures are copied as printed; whether they are percentage points or relative percentages is not stated. Figures 4-17 contain the regular-setting baselines and the PGD-AT absolute values; none of those figure values are in the text. Source code is stated to be at https://github.com/ariotedef; not verified.

MARS: certified robustness for intrusion-detection DNNs with heterogeneous features (ACM TOPS, 2025)

Security · ACM Trans. Priv. Secur. 28(3), 2025

A positive result: a certification method for intrusion-detection models against randomized-smoothing baselines, with certified and empirical robustness.

Read left to right. The question (QUE) is addressed by 5 experiments (EXP), each producing results (RES), and each result bears on the hypothesis (HYP). 4 support it, 0 oppose it, 8 inform it. Issues (ISS) hang below: what the paper leaves open.

HYP, in the authors’ words (Section 1.2 Contributions): “It achieves a tighter l2 robustness guarantee (12.23% average increase compared to BARS) and extends certification from l2 to l1 and l∞ guarantees compared to other advanced methods.”

Discourse graph of MARS: certified robustness for intrusion-detection DNNs with heterogeneous features (ACM TOPS, 2025) que addresses l2-certified-radius-vs-baselines que addresses multi-norm-certification-vs-frs que addresses evasion-attack-robust-accuracy que addresses natural-corruption-robustness que addresses distribution-alignment-and-time-cost l2-certified-radius-vs-baselines produces acid-l2-mcr-per-class acid-l2-mcr-per-class supports hyp l2-certified-radius-vs-baselines produces vrs-frs-zero-radius vrs-frs-zero-radius informs hyp l2-certified-radius-vs-baselines produces cade-l2-margin-over-bars cade-l2-margin-over-bars informs hyp multi-norm-certification-vs-frs produces fine-grained-mcr-gains fine-grained-mcr-gains supports hyp multi-norm-certification-vs-frs produces linf-radius-smallest linf-radius-smallest informs hyp multi-norm-certification-vs-frs produces dimensional-radius-goldeneye dimensional-radius-goldeneye informs hyp evasion-attack-robust-accuracy produces pgd-robust-accuracy pgd-robust-accuracy supports hyp evasion-attack-robust-accuracy produces l1-ead-still-evades l1-ead-still-evades informs hyp natural-corruption-robustness produces fine-grained-corruption-gains fine-grained-corruption-gains supports hyp natural-corruption-robustness produces bars-weakens-under-corruption bars-weakens-under-corruption informs hyp distribution-alignment-and-time-cost produces certification-time-overhead certification-time-overhead informs hyp distribution-alignment-and-time-cost produces smoothing-distribution-alignment smoothing-distribution-alignment informs hyp l2-certified-radius-vs-baselines extends multi-norm-certification-vs-frs: The l2 comparison against all three baselines is extended to l1 and l∞ against FRS only, since VRS and BARS do not support those norms. multi-norm-certification-vs-frs confirms natural-corruption-robustness: The small dimensional radii on IAT features (Table 4) are said to be consistent with the vanilla model's reduced accuracy and higher FNR on Latency-corrupted GoldenEye samples (Section 7.6.2). l2-certified-radius-vs-baselines comparedWith distribution-alignment-and-time-cost: Tables 5 and 6 report MCR and certification time side by side; the radius gains come with roughly ten-fold higher per-sample time than BARS. evasion-attack-robust-accuracy informs natural-corruption-robustness: Both are empirical-robustness tests of the same ACID detector; evasion uses the Bot class only, corruptions use benign and malicious traffic. ISS · open questions and untried branches this path leaves behind QUE · positive Can randomized smoothing with first- order gradients and dimension-wise noise give tighter lp robustness certificates for network intrusion detectors than BARS, VRS and FRS? Can randomized smoothing with first-order gradients and dimension-wise noise give tighter lp robustness certificates for network intrusion detectors than BARS, VRS and FRS? HYP MARS yields a tighter l2 certified radius than BARS (12.23% average increase), extends certification to l1 and l∞, and raises robust accuracy on evasion attacks and natural corruptions. MARS yields a tighter l2 certified radius than BARS (12.23% average increase), extends certification to l1 and l∞, and raises robust accuracy on evasion attacks and natural corruptions. EXP · positive l2 mean certified radius and certified accuracy of MARS vs VRS, FRS, BARS on CADE (2 drift datasets) and ACID (Diverse-Intrusions), CSE-CIC-IDS-2018… l2 mean certified radius and certified accuracy of MARS vs VRS, FRS, BARS on CADE (2 drift datasets) and ACID (Diverse-Intrusions), CSE-CIC-IDS-2018, 3 seeds, n_large=10,000 RES · positive On ACID, MARS l2 MCR exceeds BARS in all seven classes, e.g. Bot 2.6288 vs 2.4456 and FTP-Bruteforce 1.6832 vs 1.5814… On ACID, MARS l2 MCR exceeds BARS in all seven classes, e.g. Bot 2.6288 vs 2.4456 and FTP-Bruteforce 1.6832 vs 1.5814, while VRS and FRS give 0.0000 on both. RES · negative-not-achievable VRS and FRS, which smooth all traffic dimensions indiscriminately, fail certification (radius 0.0000) on CADE… VRS and FRS, which smooth all traffic dimensions indiscriminately, fail certification (radius 0.0000) on CADE Benign and Infiltration and on six of seven ACID classes. RES · partial On CADE the MARS gain over BARS is large only for SSH-Bruteforce (0.4744 vs 0.2450); for Benign, Infiltration and… On CADE the MARS gain over BARS is large only for SSH-Bruteforce (0.4744 vs 0.2450); for Benign, Infiltration and DoS-Hulk it is 2.0539 vs 2.0494, 3.1668 vs 3.1658 and 1.6406 vs 1.6372. EXP · positive l2, l1 and l∞ certified radius of MARS vs FRS under Gaussian smoothing (Diverse-Intrusions, Figs 10-11) and vs BARS/FRS on the four-class Similar-… l2, l1 and l∞ certified radius of MARS vs FRS under Gaussian smoothing (Diverse-Intrusions, Figs 10-11) and vs BARS/FRS on the four-class Similar-Intrusions ACID model, plus dimension-wise l2 radii RES · positive On Similar-Intrusions (DoS-GoldenEye, DoS-SlowHTTPTest, DDoS-LOIC-HTTP) MARS l2 MCR rises 9×10-4 to 3.77×10-2 over… On Similar-Intrusions (DoS-GoldenEye, DoS-SlowHTTPTest, DDoS-LOIC-HTTP) MARS l2 MCR rises 9×10-4 to 3.77×10-2 over BARS; l1 by 7.24×10-1 to 2.2373 and l∞ by 2.20×10-1 to 2.48×10-1 over FRS. RES · partial Under the same Gaussian smoothing, MARS l2 and l1 certified accuracies are close but the l∞ radius remains the smallest… Under the same Gaussian smoothing, MARS l2 and l1 certified accuracies are close but the l∞ radius remains the smallest; no numeric values are given (figures only). RES · positive Dimension-wise l2 radii on DoS-GoldenEye range from 0.0426 (Flow_IAT_Std) to 11.4358 (Fwd_Packet_Length_Min) around… Dimension-wise l2 radii on DoS-GoldenEye range from 0.0426 (Flow_IAT_Std) to 11.4358 (Fwd_Packet_Length_Min) around a class MCR of 2.2305, marking IAT features as most sensitive. EXP · positive Robust accuracy of ACID on adversarial Bot samples under white-box l2-PGD, l∞-PGD and l1-EAD (eps 1.0 / 0.2 / 1.0, 20 iterations): Vanilla vs BARS vs MARS… Robust accuracy of ACID on adversarial Bot samples under white-box l2-PGD, l∞-PGD and l1-EAD (eps 1.0 / 0.2 / 1.0, 20 iterations): Vanilla vs BARS vs MARS, 3 seeds RES · positive Robust accuracy on l∞-PGD is 88.95±0.31% for MARS vs 81.78±0.20% for BARS and 55.02±0.01% for Vanilla; on l2-PGD… Robust accuracy on l∞-PGD is 88.95±0.31% for MARS vs 81.78±0.20% for BARS and 55.02±0.01% for Vanilla; on l2-PGD 97.74±0.13% vs 96.04±0.05% vs 83.95±0.00%. RES · partial Against l1-EAD, robust accuracy is only 10.28±0.06% for MARS, versus 0.16±0.01% for BARS and 0.27±0.00% for Vanilla, so… Against l1-EAD, robust accuracy is only 10.28±0.06% for MARS, versus 0.16±0.01% for BARS and 0.27±0.00% for Vanilla, so the attack still succeeds on most samples. EXP · positive Robust accuracy, FPR and FNR of ACID under Gaussian-noise Latency and PacketLoss corruptions (sigma 0.5, 1.0, 1.5) on Diverse-Intrusions and Similar-… Robust accuracy, FPR and FNR of ACID under Gaussian-noise Latency and PacketLoss corruptions (sigma 0.5, 1.0, 1.5) on Diverse-Intrusions and Similar-Intrusions: Vanilla vs BARS vs MARS RES · positive On Similar-Intrusions MARS improves accuracy over BARS by 6.12% under Latency and PacketLoss, cuts FPR on… On Similar-Intrusions MARS improves accuracy over BARS by 6.12% under Latency and PacketLoss, cuts FPR on corrupted Benign by 4.27% and FNR on corrupted GoldenEye by 6.35%. RES · negative-no-effect On Diverse-Intrusions, BARS lowers the detector's robust accuracy on Latency and PacketLoss corruptions relative to… On Diverse-Intrusions, BARS lowers the detector's robust accuracy on Latency and PacketLoss corruptions relative to the undefended Vanilla model, while MARS raises it (figure only). EXP · partial Ablation of the smoothing distribution (Gaussian vs Laplacian vs Uniform) for l1 and l∞ certification, and average certification time per sample of MARS v… Ablation of the smoothing distribution (Gaussian vs Laplacian vs Uniform) for l1 and l∞ certification, and average certification time per sample of MARS vs VRS, FRS, BARS on CADE and ACID RES · partial MARS adds an average 21.1 ms per sample over BARS; its ACT is 8.0 to 14.6 ms on CADE and 24.4 to 36.1 ms on ACID, versu… MARS adds an average 21.1 ms per sample over BARS; its ACT is 8.0 to 14.6 ms on CADE and 24.4 to 36.1 ms on ACID, versus 0.4 to 1.3 ms and 2.9 to 5.1 ms for BARS. RES · inconclusive For l1 radii Gaussian and Laplacian each win in different classes; for l∞ the shape-matched Uniform distribution does… For l1 radii Gaussian and Laplacian each win in different classes; for l∞ the shape-matched Uniform distribution does not beat Gaussian because its bounds truncate the noise. ISS · next-step Certification time grows with first- order gradient search; authors propose hardware acceleration or distributed computing to speed up multi-order… Certification time grows with first-order gradient search; authors propose hardware acceleration or distributed computing to speed up multi-order certification. ISS · next-step Non-lp robustness certification against structural perturbations is left to future work. Non-lp robustness certification against structural perturbations is left to future work. ISS · open-question Uniform-distribution smoothing for l∞ is limited by its truncation bounds, so certification performance depends heavily on the chosen hyperparameters. Uniform-distribution smoothing for l∞ is limited by its truncation bounds, so certification performance depends heavily on the chosen hyperparameters. ISS · open-question Both detectors have inherent robustness limits: CADE certified accuracy drops rapidly beyond radius 0.5 and ACID becomes sensitive beyond 1.5, regardles… Both detectors have inherent robustness limits: CADE certified accuracy drops rapidly beyond radius 0.5 and ACID becomes sensitive beyond 1.5, regardless of certification method.
  • supports positive finding
  • opposes a null, worse or failed result against a control or tuned baseline, with a reported test, interval or variance to show it is real
  • informs bears on the question without deciding the hypothesis
  • thin grey a relation between two experiments
Nodes, in reading order. Sources: Huang, Lin, Chen & Bertino 2025, 10.1145/3715121; version of record from the ACM Digital Library, CC BY 4.0, read in full on 19 October 2026.
NodeTextTypeOutcomeEdge
EXPl2 mean certified radius and certified accuracy of MARS vs VRS, FRS, BARS on CADE (2 drift datasets) and ACID (Diverse-Intrusions), CSE-CIC-IDS-2018, 3 seeds, n_large=10,000
MARS reports the highest per-class l2 MCR in every class, but the margin over BARS is often in the third decimal place; VRS and FRS return radius 0 in many classes.
benchmark comparisonpositive
RESOn ACID, MARS l2 MCR exceeds BARS in all seven classes, e.g. Bot 2.6288 vs 2.4456 and FTP-Bruteforce 1.6832 vs 1.5814, while VRS and FRS give 0.0000 on both.
l2 MCR, ACID, Table 6: Bot MARS 2.6288, BARS 2.4456, FRS 0.0000, VRS 0.0000; FTP-Bruteforce MARS 1.6832, BARS 1.5814; Benign MARS 1.9260, BARS 1.9036, FRS 1.2077, VRS 0.1950; average of 3 seeds {42,43,44}, no variance given
Section 7.1.2, Figure 9, Table 6 · “the improvement brought by MARS has always been greater than BARS”
positive
informative
supports HYP
RESVRS and FRS, which smooth all traffic dimensions indiscriminately, fail certification (radius 0.0000) on CADE Benign and Infiltration and on six of seven ACID classes.
l2 MCR = 0.0000 for VRS and FRS on CADE Benign and Infiltration (Table 5) and on FTP-Bruteforce, DDoS-HOIC, Bot, DDoS-LOIC-HTTP (Table 6); FRS DoS-GoldenEye 0.0024, DoS-SlowHTTPTest 0.0014
Section 7.1.2, Tables 5 and 6 · “MARS showed significant advantages over BARS when both VRS and FRS failed certification in many categories”
negative-not-achievable
informative
informs HYP
RESOn CADE the MARS gain over BARS is large only for SSH-Bruteforce (0.4744 vs 0.2450); for Benign, Infiltration and DoS-Hulk it is 2.0539 vs 2.0494, 3.1668 vs 3.1658 and 1.6406 vs 1.6372.
l2 MCR, CADE, Table 5: Benign MARS 2.0539 / BARS 2.0494; SSH-Bruteforce 0.4744 / 0.2450; Infiltration 3.1668 / 3.1658; DoS-Hulk 1.6406 / 1.6372; 3 seeds, no variance given
Table 5 · “MARS 2.0539 (0.0096) 0.4744 (0.0133) 3.1668 (0.0131) 1.6406 (0.0146)”
partial
informative
informs HYP
EXPl2, l1 and l∞ certified radius of MARS vs FRS under Gaussian smoothing (Diverse-Intrusions, Figs 10-11) and vs BARS/FRS on the four-class Similar-Intrusions ACID model, plus dimension-wise l2 radii
MARS gives non-trivial l1 and l∞ radii where FRS returns 0, and the largest MCR under all three norms in fine-grained detection, but l∞ radii stay smallest.
benchmark comparisonpositive
RESOn Similar-Intrusions (DoS-GoldenEye, DoS-SlowHTTPTest, DDoS-LOIC-HTTP) MARS l2 MCR rises 9×10-4 to 3.77×10-2 over BARS; l1 by 7.24×10-1 to 2.2373 and l∞ by 2.20×10-1 to 2.48×10-1 over FRS.
MCR increase, ACID four-class model on Similar-Intrusions: l2 +9×10-4 to +3.77×10-2 vs BARS; l1 +7.24×10-1 to +2.2373 vs FRS; l∞ +2.20×10-1 to +2.48×10-1 vs FRS; 3 seeds, no variance given (Figure 13)
Section 7.5.2, Figure 13 · “l2 radius increased by 9×10-4 to 3.77×10-2 compared to BARS, l1 by 7.24×10-1 to 2.2373 and l∞ by 2.20×10-1 to 2.48×10-1 compared to FRS”
positive
informative
supports HYP
RESUnder the same Gaussian smoothing, MARS l2 and l1 certified accuracies are close but the l∞ radius remains the smallest; no numeric values are given (figures only).
certified accuracy and MCR by norm, Diverse-Intrusions, Figures 10 and 11; no numbers in text
Section 7.2.2, Figures 10 and 11 · “l2 and l1 radii are close, but the l∞ radius remains the smallest, as l∞ is the most difficult to capture by the Gaussian distribution”
partial
informative
informs HYP
RESDimension-wise l2 radii on DoS-GoldenEye range from 0.0426 (Flow_IAT_Std) to 11.4358 (Fwd_Packet_Length_Min) around a class MCR of 2.2305, marking IAT features as most sensitive.
l2 dimensional MCR, ACID, DoS-GoldenEye, Table 4: Flow_IAT_Std 0.0426, Bwd_Packet_Length_Std 0.0433, Active_Std 0.0488, Init_Win_bytes_forward 0.0569, Active_Max 0.0576; Flow_Duration 10.0741, Fwd_URG_Flag 10.9644, RST_Flag_Count 11.2367, Bwd_PSH_Flag 11.3300, Fwd_Packet_Length_Min 11.4358; class MCR 2.2305
Section 7.6.2, Table 4, Figure 15 · “the model demonstrates greater sensitivity to inter arrival time (IAT)-related features while showing greater robustness to forward packet length-related features”
positive
informative
informs HYP
EXPRobust accuracy of ACID on adversarial Bot samples under white-box l2-PGD, l∞-PGD and l1-EAD (eps 1.0 / 0.2 / 1.0, 20 iterations): Vanilla vs BARS vs MARS, 3 seeds
MARS has the highest robust accuracy on all three attacks with seed variance reported, but l1-EAD still evades it 90% of the time.
benchmark comparisonpositive
RESRobust accuracy on l∞-PGD is 88.95±0.31% for MARS vs 81.78±0.20% for BARS and 55.02±0.01% for Vanilla; on l2-PGD 97.74±0.13% vs 96.04±0.05% vs 83.95±0.00%.
Robust accuracy (%), ACID, adversarial Bot samples, Table 3: l∞-PGD Vanilla 55.02±00.01, BARS 81.78±00.20, MARS 88.95±00.31; l2-PGD Vanilla 83.95±00.00, BARS 96.04±00.05, MARS 97.74±00.13; clean accuracy 100.00±00.00 for all; 3 seeds {42,43,44}
Section 7.3.2, Table 3 · “our defense boosts the robust accuracy against evasion attacks by 1.70% for l2-PGD, 7.17% for l∞-PGD, and 10.11% for l1-EAD”
positive
informative
supports HYP
RESAgainst l1-EAD, robust accuracy is only 10.28±0.06% for MARS, versus 0.16±0.01% for BARS and 0.27±0.00% for Vanilla, so the attack still succeeds on most samples.
Robust accuracy (%) on l1-EAD, ACID Bot, Table 3: Vanilla 00.27±00.00, BARS 00.16±00.01, MARS 10.28±00.06; 3 seeds
Section 7.3.2, Table 3 · “Neither Vanilla nor BARS can resist l1-EAD, and only MARS enhances model robustness against it.”
partial
informative
informs HYP
EXPRobust accuracy, FPR and FNR of ACID under Gaussian-noise Latency and PacketLoss corruptions (sigma 0.5, 1.0, 1.5) on Diverse-Intrusions and Similar-Intrusions: Vanilla vs BARS vs MARS
MARS has the highest robust accuracy at every corruption strength; BARS falls below the undefended model on corruptions; only the fine-grained experiment reports numbers.
benchmark comparisonpositive
RESOn Similar-Intrusions MARS improves accuracy over BARS by 6.12% under Latency and PacketLoss, cuts FPR on corrupted Benign by 4.27% and FNR on corrupted GoldenEye by 6.35%.
accuracy +6.12% vs BARS under Latency and PacketLoss; FPR on corrupted Benign -4.27%; FNR on corrupted DoS-GoldenEye -6.35%; ACID four-class model; Figure 14; no variance given
Section 7.5.2, Figure 14 · “FPR on corrupted Benign samples decreased by 4.27%, and FNR on corrupted GoldenEye decreased by 6.35%”
positive
informative
supports HYP
RESOn Diverse-Intrusions, BARS lowers the detector's robust accuracy on Latency and PacketLoss corruptions relative to the undefended Vanilla model, while MARS raises it (figure only).
robust accuracy vs corruption sigma in {0.5, 1.0, 1.5}, ACID, Figure 12; no numbers in text
Section 7.4.2, Figure 12 · “Compared with the enhanced robustness from MARS, BARS weakens the detector’s ability to identify natural corruptions.”
negative-no-effect
informative
informs HYP
EXPAblation of the smoothing distribution (Gaussian vs Laplacian vs Uniform) for l1 and l∞ certification, and average certification time per sample of MARS vs VRS, FRS, BARS on CADE and ACID
No single smoothing distribution wins for l1, Uniform does not beat Gaussian for l∞, and MARS costs about 21.1 ms more per sample than BARS.
ablationpartial
RESMARS adds an average 21.1 ms per sample over BARS; its ACT is 8.0 to 14.6 ms on CADE and 24.4 to 36.1 ms on ACID, versus 0.4 to 1.3 ms and 2.9 to 5.1 ms for BARS.
ACT per sample: MARS CADE 0.0096-0.0146 s, ACID 0.0244-0.0361 s; BARS CADE 0.0004-0.0013 s, ACID 0.0029-0.0051 s; average increase 21.1 ms; Tables 5 and 6; RTX 3090
Section 7.8.2, Tables 5 and 6 · “MARS achieves the highest MCR across all competitions, with an average increase in ACT per sample of 21.1 milliseconds (ms)”
partial
informative
informs HYP
RESFor l1 radii Gaussian and Laplacian each win in different classes; for l∞ the shape-matched Uniform distribution does not beat Gaussian because its bounds truncate the noise.
l1 MCR by class under Gaussian, Laplacian, Uniform (Figure 16); l∞ result stated without figure or numbers; Uniform bounds -sqrt(3) to sqrt(3), Gaussian and Laplacian mean 0 sd 1
Section 7.7.2, Figure 16 · “Gaussian and Laplacian distributions each excel in different classes, indicating that simply using a single distribution may miss a tighter certified radius”
inconclusive
informative
informs HYP
  • ISS Certification time grows with first-order gradient search; authors propose hardware acceleration or distributed computing to speed up multi-order certification. (next-step · Section 7.8.2)
  • ISS Non-lp robustness certification against structural perturbations is left to future work. (next-step · Section 9 Conclusion)
  • ISS Uniform-distribution smoothing for l∞ is limited by its truncation bounds, so certification performance depends heavily on the chosen hyperparameters. (open-question · Section 7.7.2)
  • ISS Both detectors have inherent robustness limits: CADE certified accuracy drops rapidly beyond radius 0.5 and ACID becomes sensitive beyond 1.5, regardless of certification method. (open-question · Section 7.1.2)

Extraction notes: Text is the ACM Transactions on Privacy and Security version (Vol. 28, No. 3, Article 40, August 2025, CC BY 4.0), an extended version of a TrustCom 2024 paper [16]. The PDF extraction collapses many spaces; quotes have had spacing restored but no words changed. All three baselines (VRS, FRS, BARS) were run by the authors on the same datasets with seeds {42,43,44} and averages reported (Section 6.1), so none of the baseline numbers is copied from another paper; however only Table 3 reports a ± variance; Tables 4-6 and all figures give point values only. Self-inconsistencies in the paper: the abstract says natural-corruption gains of 16.65% (latency) and 18.23% (packet loss) 'compared to the SOTA method' while Section 1.2 says 16.87% and 19.85% 'compared to the base model', and neither pair appears in Section 7.4, which gives only Figure 12; the l∞-PGD gain over Vanilla is 33.93% in Section 1.2 and 33.94% in Section 7.3.2; the headline '12.23% average increase' in l2 certified radius is stated in the abstract and contributions but is not located in any results table, and the per-class l2 MCR margins over BARS in Tables 5 and 6 are mostly in the third decimal place (my reading). Section 6.5.1 and 7.3.1 configure an l1-PGD attack but Table 3 has no l1-PGD column; the text says the base ACID detector was already robust to it, without numbers. Evasion-attack evaluation is on ACID and the Bot class only, following the BARS setup; CADE is not attacked empirically. The multi-norm comparison in Section 7.2 is against FRS alone and reported only as figures. Table 1 (property grid of methods) lost its check marks in extraction. The outcomeClass 'inconclusive' with valence 'informs' on the smoothing-distribution ablation is my call: it is a secondary design-component result with no numbers, not a test of the central claim. Labelling BARS 'negative-no-effect' under corruption is also my reading of the sentence quoted, backed only by Figure 12.

Licence and what this page is

All eleven papers are CC BY 4.0 on the version of record, so the graphs are published here with attribution; each links to the paper it was read from and quotes it only in short. The graphs are a view of what each paper claims and found, drawn by one extraction pass against a written brief and checked by hand on the headline numbers. They are not the authors’ own summary, and the extraction notes under each graph record what was inferred and what could not be resolved. Corrections from the authors are welcome. The proposal is the same as for the other sets: a publisher could authorise graphs of its own papers, drawn into the fields a Negative-Results Record already holds, and these are what the first ones would look like.

Method: OpenAlex, ACM publisher lineage, article type, licence cc-by on the primary location, two searches (most cited; titles and abstracts mentioning replication, reproducibility, null or negative wording) for the first eight, author record A5061694501 filtered the same way for the three security papers, licence verified per paper via Crossref content-version vor; versions of record fetched from dl.acm.org inside a browser session and converted from PDF; one extraction pass per paper following a written brief, each finding with a locator and a quote; the JSON for each graph is kept with the brief.