Reconstructing the benchmark behind Luc Julia's 64% LLM reliability claim A reconstruction of the reasoning benchmark behind Luc Julia's repeated claim that large language models are 'relevant 64% of the time' shows the figure comes from a single sentence in Bang et al. (2023), which reported 63.41% accuracy on 634 hand-picked questions, not the 'millions' of facts Julia has cited. The reconstruction, released as a runnable repository, scores GPT-3.5 at 63.41%, GPT-5.6 Sol at 96.50%, and Claude Opus 5 at 98.50% on a balanced 200-question subset. Julia, Chief Scientific Officer at Renault and often called a Siri co-creator, repeated the claim before the French Senate on 18 June 2025, but the original experiment was a reasoning evaluation, not a fact-verification task, and the rounding from 63.41% to 64% is mathematically incorrect. A runnable version of the reasoning benchmark behind the "64%" accuracy figure that Luc Julia often introduced in French media as a co-creator of Siri has repeated for years as the general "reliability rate" of large language models. The number comes from a single sentence in the abstract of Bang et al. 2023 https://aclanthology.org/2023.ijcnlp-main.45/ whose reasoning evaluation graded a December 2022 ChatGPT snapshot on 634 hand-picked questions drawn from 22 series across ten categories. This repository rebuilds that evaluation from the paper and its released extraction code, reduces it to a balanced 200-question set, and documents an explicit grading rule so that any model can be scored on the same task today. Everything needed to reproduce a run is here: the questions and gold answers in data.csv , ten shuffled part .csv files to hand to a model, the merge and scoring scripts, and a per-benchmark description of where each item comes from. | Model | Score | Source | |---|---|---| GPT-3.5 | 63.41% | Original paper | GPT-5.6 Sol | 96.50% | This reconstruction | Claude Opus 5 | 98.50% | This reconstruction | The "64%" figure incorrectly rounded from 63.41% has had a public life well beyond the paper it comes from. In France it circulates as a general "reliability rate" of large language models. Its most visible proponent is Luc Julia, Chief Scientific Officer at Renault and routinely introduced in French media as a co-creator of Siri, who has repeated it for years in interviews, in his 2025 book, and on 18 June 2025 before the French Senate's Commission des affaires économiques: generative AIs are, in his words, "relevant 64% of the time ... that is, 36% of the time the AI says that something true is false." He has also stated on several occasions that the figure is lower today than when it was measured, because the web that models train on is now saturated with AI-generated text. Sources: Senate hearing https://www.senat.fr/actualite/ia-audition-de-luc-julia-concepteur-de-siri-5387.html video https://videos.senat.fr/video.5486945 685259f55eac4.ia--audition-de-luc-julia-concepteur-de-siri , Public Sénat coverage https://www.publicsenat.fr/actualites/societe/intelligence-artificielle-laudition-de-luc-julia-le-createur-de-siri-qui-a-enflamme-les-reseaux-sociaux , European Scientist interview https://www.europeanscientist.com/fr/opinion/chatgpt-cest-64-de-pertinence-il-faut-toujours-douter-de-lia-luc-julia-interview/ . Critical analyses of the claim: AFIS https://www.afis.org/La-controverse-autour-de-Luc-Julia-sur-l-intelligence-artificielle , nocodefunctions https://nocodefunctions.com/blog/luc-julia-ia-nuances-confusions/ . Three problems are worth separating: - The experiment described is not the experiment that was run. Julia has presented the number as the result of a study in which researchers submitted a very large set of verified facts "millions", in some tellings to ChatGPT and asked it to judge each one true or false. Bang et al. did nothing of the kind. The 63.41% is answer accuracy over 634 manually judged trials , hand-selected from 22 series across ten reasoning categories: deductive, inductive, abductive, mathematical, temporal, spatial, commonsense, causal, multi-hop, and analogical. There is no true/false fact-verification task anywhere in it, and no "millions" of anything: the entire reasoning evaluation is the 634 items reconstructed in this pack. The provenance is not even stable across retellings: the same interview points to arXiv:2302.12095 https://arxiv.org/abs/2302.12095 , a different paper on robustness to adversarial and misspelled prompts, and at least one version attributes the decline to an OpenAI report that nobody has been able to locate. The rounding does not survive contact either: 63.41 does not round to 64. It is possible the "64" comes from the February 2023 v1 abstract, which reported 64.33% over 600 samples before the final version revised it, but that is a reconstruction, not something the claim itself makes clear. - A single accuracy number is not a property of a model. It is a property of a model and a fixed question set. Bang et al. deliberately assembled hard reasoning items on which a late-2022 model was expected to struggle; move the difficulty and the same model returns any figure between 0% and 100%. Speaking of "the reliability rate of LLMs", without naming the questions, is a category error, and it is the reason a number measured once on one December 2022 snapshot cannot be carried forward as a standing property of a technology. - The claim that today's models would score lower is testable, which is the point of this pack. Benchmark after benchmark has gone from near-zero to saturated across successive model generations, so the prediction that a 2026 model underperforms GPT-3.5 on GPT-3.5's own evaluation set is a strong one. Rather than argue it, this repository reconstructs the evaluation and runs it: the results are in the table above. Note what this does and does not settle. It measures current models on the exact task behind the 63.41%, under a documented and auditable grading rule. It does not measure "reliability" in general, and no honest reading of a single benchmark could. This pack reconstructs only the reasoning evaluation behind the 63.41% sentence in the abstract of Bang et al. 2023 , not the paper's summarization, translation, sentiment, dialogue, multimodal, misinformation, or hallucination experiments. The final paper evaluated the 15 December 2022 ChatGPT snapshot in a zero-shot, manually judged setting. Primary references: ACL Anthology paper https://aclanthology.org/2023.ijcnlp-main.45/ , current arXiv record https://arxiv.org/abs/2302.04023 , arXiv v1 PDF https://arxiv.org/pdf/2302.04023v1 , and official extraction repository https://github.com/HLTCHKUST/chatgpt-evaluation . The paper and code do not define a single, fully reproducible formula that independently yields 63.41%. This reconstruction therefore preserves the released prompts, source ordering, and the final paper's trial allocation as closely as possible, while making the scoring rule explicit. - The February 2023 v1 abstract reported 64.33% and 600 reasoning samples; the final paper reports 63.41% and 634 samples. - For the Mathematics Dataset, Section 3 and Appendix F.2 say 7/30 , while Table 5 says 13/30 . - One sentence in the main text swaps bAbI task 15/16 labels, whereas Appendix Table 11 and the repository consistently treat task 15 as deductive and task 16 as inductive. - The final 634-trial accounting can be reconstructed as 17 series of 30, two SpaRTQA series of 32, and three StepGame diagnostics of 20: 17×30 + 2×32 + 3×20 = 634 . This count includes separate as-is and prompt-engineered runs over the same bAbI items, plus overlapping StepGame diagnostic items. - The released StepGame basic function removes ID 4 for a wrong gold label and thus returns 29 items even though the paper reports 30. The reduced set follows the code and excludes that item. - The released analogy extractor names a legacy NPZ that is absent upstream. The two selected problem-type indices 4 and 5 correspond to fix alphabet and sort in the upstream generator, so those types are reconstructed from the available all prob.npz . The reduced set contains exactly 200 rows . Counts were chosen by simple, interpretable sub-allocations rather than by forcing every benchmark to the same size: most 30-item series contribute 9 rows; MATH contributes 2 from each of 6 modules; each SpaRTQA series contributes 3 from each of 4 question types; the three StepGame diagnostics contribute 6 each; PEP-3k contributes 5 positive and 5 negative predicates; and letter analogies contribute 5 from each of 2 problem types. The 200 questions themselves live in data.csv and in the ten part .csv files. The per-benchmark sections that follow document each series and show one sample question from it, so that the prompt format and the expected-answer convention are visible without reproducing the whole set here. | Category | Benchmark / series | Original trials | Reduced trials | |---|---|---|---| | Deductive reasoning | EntailmentBank | 30 | 9 | | Deductive reasoning | bAbI task 15 as-is | 30 | 9 | | Deductive reasoning | bAbI task 15 prompt-engineered | 30 | 9 | | Inductive reasoning | CLUTRR | 30 | 9 | | Inductive reasoning | bAbI task 16 as-is | 30 | 9 | | Inductive reasoning | bAbI task 16 prompt-engineered | 30 | 9 | | Abductive reasoning | alphaNLI | 30 | 9 | | Mathematical reasoning | DeepMind Mathematics Dataset | 30 | 12 | | Temporal reasoning | TimeDial | 30 | 9 | | Spatial reasoning | SpaRTQA one reasoning type | 32 | 12 | | Spatial reasoning | SpaRTQA two reasoning types | 32 | 12 | | Spatial reasoning | StepGame hard, k=9 | 30 | 9 | | Spatial reasoning | StepGame basic, k=1 | 30 | 9 | | Spatial reasoning | StepGame basic cardinal diagnostic | 20 | 6 | | Spatial reasoning | StepGame diagonal diagnostic | 20 | 6 | | Spatial reasoning | StepGame clock-position diagnostic | 20 | 6 | | Commonsense reasoning | CommonsenseQA | 30 | 9 | | Commonsense reasoning | PIQA | 30 | 9 | | Commonsense reasoning | PEP-3k | 30 | 10 | | Causal reasoning | E-CARE | 30 | 9 | | Multi-hop reasoning | HotpotQA | 30 | 9 | | Analogical reasoning | Letter-string analogies | 30 | 10 | Total | 634 | 200 | First 9 examples of the Task 1 test split, matching the official extractor's first-N rule. The v3 Task 1 data are used. The prompt concatenates the provided entailment facts and the ARC-derived question. Dataset/source https://allenai.org/data/entailmentbank ; paper extraction code https://github.com/HLTCHKUST/chatgpt-evaluation/blob/main/src/reasoning qa.py L422-L471 . | Sample question | Expected answer | |---|---| | if a place is in summer, then it will have the most sunlight. the northern hemisphere is a kind of hemisphere of earth. a hemisphere of earth is a kind of place. Melinda learned that days in some seasons have more daylight hours than in other seasons. Which season receives the most hours of sunlight in the Northern Hemisphere? | summer | First 9 story-question blocks from qa15 basic-deduction test.txt. The numbered bAbI facts and question are retained as in the official extractor. Dataset/source https://research.facebook.com/downloads/babi/ ; paper extraction code https://github.com/HLTCHKUST/chatgpt-evaluation/blob/main/src/reasoning qa.py L319-L420 . | Sample question | Expected answer | |---|---| | 1 Wolves are afraid of mice. 2 Sheep are afraid of mice. 3 Winona is a sheep. 4 Mice are afraid of cats. 5 Cats are afraid of wolves. 6 Jessica is a mouse. 7 Emily is a cat. 8 Gertrude is a wolf. 9 What is emily afraid of? 10 What is winona afraid of? 11 What is gertrude afraid of? 12 What is jessica afraid of? | wolf / mouse / mouse / cat | The same first 9 task-15 blocks, transformed with the repository's deductive-reasoning prompt. These are deliberately separate trials: the underlying questions duplicate the as-is set, but the prompts differ. Dataset/source https://research.facebook.com/downloads/babi/ ; paper extraction code https://github.com/HLTCHKUST/chatgpt-evaluation/blob/main/src/reasoning qa.py L319-L420 . | Sample question | Expected answer | |---|---| | Given facts: Wolves are afraid of mice. Sheep are afraid of mice. Winona is a sheep. Mice are afraid of cats. Cats are afraid of wolves. Jessica is a mouse. Emily is a cat. Gertrude is a wolf. The most recent fact is the correct fact. Based on the given facts above, do a reasonable inference on this question using deductive reasoning: What is emily afraid of? What is winona afraid of? What is gertrude afraid of? What is jessica afraid of? | wolf / mouse / mouse / cat | First 9 test examples from config gen train23 test2to10. The clean story is followed by the kinship query in the same orientation as the official extractor. Dataset/source https://huggingface.co/datasets/CLUTRR/v1 ; paper extraction code https://github.com/HLTCHKUST/chatgpt-evaluation/blob/main/src/reasoning qa.py L522-L564 . | Sample question | Expected answer | |---|---| | Scott and Lewis are brothers. Jason is father of their father. Who is Lewis to Jason? | grandson | First 9 story-question blocks from qa16 basic-induction test.txt. The numbered bAbI facts and question are retained as in the official extractor. Dataset/source https://research.facebook.com/downloads/babi/ ; paper extraction code https://github.com/HLTCHKUST/chatgpt-evaluation/blob/main/src/reasoning qa.py L319-L420 . | Sample question | Expected answer | |---|---| | 1 Lily is a swan. 2 Bernhard is a lion. 3 Greg is a swan. 4 Bernhard is white. 5 Brian is a lion. 6 Lily is gray. 7 Julius is a rhino. 8 Julius is gray. 9 Greg is gray. 10 What color is Brian? | white | The same first 9 task-16 blocks, transformed with the repository's inductive-reasoning prompt. These are deliberately separate trials: the underlying questions duplicate the as-is set, but the prompts differ. Dataset/source https://research.facebook.com/downloads/babi/ ; paper extraction code https://github.com/HLTCHKUST/chatgpt-evaluation/blob/main/src/reasoning qa.py L319-L420 . | Sample question | Expected answer | |---|---| | Given facts: Lily is a swan. Bernhard is a lion. Greg is a swan. Bernhard is white. Brian is a lion. Lily is gray. Julius is a rhino. Julius is gray. Greg is gray. The most recent fact is the correct fact. Based on the given facts above, do a reasonable inference on this question using inductive reasoning: What color is Brian? | white | First 9 examples and labels from the alphaNLI test split. The expected answer gives both the A/B label and its hypothesis text; the original labels are 1/2. Dataset/source https://abductivecommonsense.xyz/ ; paper extraction code https://github.com/HLTCHKUST/chatgpt-evaluation/blob/main/src/reasoning qa.py L473-L520 . | Sample question | Expected answer | |---|---| | Given: Jane was a professor teaching piano to students. Then: Jane spent the morning sipping coffee and reading a book. Select the most plausible explanation hypothesis : A. Two of Jane's students were early for their lessons. B. None of Jane's students had a lesson that day. | B. None of Jane's students had a lesson that day. | First 2 of the 5 paper-selected examples in each of 6 modules: linear algebra, add/subtract, differentiation, closest comparison, unit conversion, and base conversion. The official repository redistributes the exact 30 paper examples in math deepmind 30 samples.csv; this subset preserves all six modules. Dataset/source https://github.com/google-deepmind/mathematics dataset ; paper extraction code https://github.com/HLTCHKUST/chatgpt-evaluation/blob/main/src/reasoning qa.py L115-L141 . | Sample question | Expected answer | |---|---| | Solve -282 d + 929 - 178 = -1223 for d. | 7 | First 9 test examples, matching the official extractor's first-N rule. TimeDial exposes two correct and two incorrect candidate completions; both correct candidates are accepted unless the second is 'none'. Dataset/source https://github.com/google-research-datasets/TimeDial ; paper extraction code https://github.com/HLTCHKUST/chatgpt-evaluation/blob/main/src/reasoning qa.py L143-L178 . | Sample question | Expected answer | |---|---| | Given the conversation: A:We need to take the accounts system offline to carry out the upgrade . But don't worry , it won't cause too much inconvenience . We're going to do it over the weekend . B: How long will the system be down for ? A: We'll be taking everything offline in about two hours ' time . It'll be down for a minimum of twelve hours . If everything goes according to plan , it should be up again by 6 pm on Saturday . B: That's fine . We've allowed