Satcove Research · Benchmark of 22 October 2026
AI Consensus Is a Signal, Not a Scoreboard
We ran 2,500 questions with known answers through up to six AI models. Agreement tracked correctness, but unanimity was not proof.
The short answer
AI agreement is a useful signal, not proof.
We asked up to six AI models 2,500 questions with known answers.
- When they all gave the same answer, it was right 94.0% of the time (1,148 of 1,221).
- Yet 73 of those unanimous answers were wrong.
- When they split and agreement fell below 60%, the majority was right only 33.5% of the time.
So Satcove reads agreement as a signal, and disagreement as a reason to verify.
Key Findings
Four results carry the study: how often unanimous answers were right, how often they were wrong, how fast accuracy fell when models split, and how the majority compared with the best single model.
2,500
questions with a known answer
MMLU-Pro, TruthfulQA, PubMedQA, GPQA Diamond
94.0%
of unanimous answers were correct
1,148 of 1,221 unanimous questions
73
unanimous answers were wrong
6.0% of unanimous questions
33.5%
majority accuracy below 60% agreement
194 questions with a majority; 197 ties
- Measured: the more the models agreed, the more often the majority answer matched the known answer, from 94.0% (unanimous) down to 33.5% (weak agreement).
- Measured: on the 2,303 questions that had a majority, the majority scored 77.1% and Claude alone 77.5%. The majority did not clearly beat the strongest single model.
- Interpretation: the value of several models is less a higher score than a visible signal: how much they agree, where they split, and what to verify.
Agreement Tracks Accuracy, but Does Not Guarantee It
When all models gave the same answer, it was correct 94.0% of the time. Majority accuracy then fell to 70.5%, 56.2% and 33.5% as agreement weakened. This is an association measured on multiple-choice questions, not proof that agreement causes accuracy.
Unanimous: 94.0%
1,221 questions · 1,221 with a majority answer · 1,148 correct · 95% CI 92.5–95.2%
Every answering model gave the same letter. This is the strongest agreement signal, and still not a guarantee.
Higher agreement means the panel converged more. It is a useful signal, not a guarantee. Final data, including second-pass answers. Jury of 4 to 6 models per question. Wilson 95% intervals.
| Agreement level | Questions | With a majority | Correct | Accuracy | 95% interval |
|---|---|---|---|---|---|
| Unanimous | 1,221 | 1,221 | 1,148 | 94.0% | 92.5–95.2% |
| Strong agreement (80% or more) | 440 | 440 | 310 | 70.5% | 66–74.5% |
| Clear majority (60-79%) | 448 | 448 | 252 | 56.2% | 51.6–60.8% |
| Weak agreement or tie (under 60%) | 391 | 194 | 65 | 33.5% | 27.2–40.4% |
Source: benchmark dataset, final data including second-pass answers. Accuracy is computed on questions with a majority answer; the 197 exact ties all fall in the weak-agreement row and are excluded from its accuracy. Intervals are Wilson 95%.
73 Times, Every Model Was Wrong Together
A false consensus is a question where every answering model gave the same wrong answer. It happened 73 times in 2,500 questions: 44 in MMLU-Pro, 15 in TruthfulQA, 9 in PubMedQA and 5 in GPQA Diamond. Unanimity raises confidence. It does not remove shared blind spots.
Why it matters. These are the cases a majority-only view cannot flag: every model agreed, so nothing looked uncertain.
12 of 73 cases
MMLU-Pro · math
5 models all answered D
Correct answer: H
MMLU-Pro · other
5 models all answered C
Correct answer: B
MMLU-Pro · philosophy
5 models all answered I
Correct answer: B
MMLU-Pro · physics
6 models all answered A
Correct answer: F
MMLU-Pro · other
5 models all answered A
Correct answer: D
MMLU-Pro · other
5 models all answered C
Correct answer: D
MMLU-Pro · philosophy
5 models all answered B
Correct answer: I
MMLU-Pro · philosophy
5 models all answered A
Correct answer: D
MMLU-Pro · physics
6 models all answered A
Correct answer: C
MMLU-Pro · psychology
5 models all answered F
Correct answer: A
GPQA Diamond · chemistry
5 models all answered B
Correct answer: A
GPQA Diamond · chemistry
5 models all answered D
Correct answer: B
Why can't you open the question? We have not been able to confirm that the source question sets allow us to republish their text, and GPQA asks not to publish its questions at all. So each card shows only the source, the topic, how many models answered and the letters. The full list, with every model's letter, is in the downloadable answers file.
| Source | Unanimous | Wrong | Share wrong |
|---|---|---|---|
| GPQA Diamond | 43 | 5 | 11.6% |
| MMLU-Pro | 696 | 44 | 6.3% |
| PubMedQA | 127 | 9 | 7.1% |
| TruthfulQA (mc1) | 355 | 15 | 4.2% |
Source: benchmark dataset, final data. GPQA rests on 43 unanimous questions, so its percentage is imprecise.
Model Results: Scope Matters More Than Rank
Single-model accuracy ranged from 63.6% to 74.7%, but the models did not all answer the same questions, and some scores include second-pass answers. Perplexity answered a separate 533-question sample, so it must not be read against the others on 2,500 questions. This is not a leaderboard.
| Model | Version tested | Questions answered | Accuracy | 95% interval | Notes |
|---|---|---|---|---|---|
| Claude | claude-sonnet-4-6 | 2,500 | 74.7% | 73–76.4% | Includes 475 recovered answers |
| Gemini | gemini-3.5-flash-lite | 2,499 | 69.9% | 68.1–71.7% | Includes 85 recovered answers |
| Mistral | mistral-large-latest | 2,499 | 67.5% | 65.6–69.3% | Includes 7 recovered answers |
| GPT | gpt-4o-2024-08-06 | 2,500 | 63.8% | 61.9–65.7% | No recovered answers |
| Grok | grok-4.20-0309-non-reasoning | 2,500 | 63.6% | 61.7–65.5% | Includes 1 recovered answer |
| Perplexity | sonar | 533 | 70.0% | 66–73.7% | Run on 533 questions only; includes 86 recovered answers |
Source: benchmark dataset, final data. Letter-only multiple choice; model versions are the exact identifiers returned by each API on 22 October 2026. Four of the six identifiers are undated aliases. These versions are not necessarily the models in Satcove's current panel.
| Model | Correct | Accuracy | 95% interval |
|---|---|---|---|
| Claude | 409 / 533 | 76.7% | 73–80.1% |
| Gemini | 382 / 533 | 71.7% | 67.7–75.3% |
| Perplexity | 373 / 533 | 70.0% | 66–73.7% |
| Mistral | 366 / 533 | 68.7% | 64.6–72.5% |
| Grok | 353 / 533 | 66.2% | 62.1–70.1% |
| GPT | 341 / 533 | 64.0% | 59.8–67.9% |
Source: benchmark dataset, final data, questions where Perplexity and every other model gave a valid letter (533). This is the only fair comparison that includes Perplexity.
Why second-pass answers matter. 654 answers came from a second pass for replies that had no usable letter. They were right less often than first-pass answers: Claude 46.9% on 475 recovered answers against 81.2% on 2,025 first-pass answers. The first pass failed mostly on hard questions, so Claude's overall score depends on this mechanism. We report both views.
Majority Vote vs. the Best Single Model
Not clearly. On the 2,303 questions where a majority existed, the majority answer was right 77.1% of the time and Claude alone 77.5%. Counting the 197 ties as failures, the majority drops to 71% on all 2,500 questions.
| Measure | Questions | Correct | Accuracy |
|---|---|---|---|
| Majority answer (ties excluded) | 2,303 | 1,775 | 77.1% |
| Claude on the same questions | 2,303 | 1,785 | 77.5% |
| Majority, ties counted as failures | 2,500 | 1,775 | 71% |
Source: benchmark dataset, final data. The majority is computed on 2,303 questions (ties excluded); individual scores in the first table cover 2,500 questions. Claude's figure here is restricted to the same 2,303 questions.
On this benchmark, majority voting performed essentially on par with the strongest individual model rather than clearly surpassing it. The case for comparing several models is therefore not a higher raw score. It is that one model does not tell you when it is wrong, and agreement among several does tell you how much to check.
Not Every Question Had Six Voters
The number of models answering varied: five on 1,965 questions, six on 533 and four on 2. A unanimity of five is easier to reach than a unanimity of six, so we also report a constant jury of five and a constant jury of six. The conclusion holds in both.
1,965
questions answered by 5 models
Claude, GPT, Gemini, Mistral and Grok.
533
questions answered by 6 models
The same five plus Perplexity.
Why not six everywhere? Perplexity ran on a fixed sample of 533 questions instead of all 2,500, to limit cost. Two further questions had only four valid answers, so they are counted in the totals but not shown here.
| View | Questions | Majority accuracy | Unanimous | Unanimous wrong |
|---|---|---|---|---|
| Headline: final data, 4 to 6 models | 2,500 | 77.1% | 1,221 | 73 (6.0%) |
| Constant jury of 5 | 2,498 | 77.2% | 1,235 | 80 (6.5%) |
| Constant jury of 6 (Perplexity questions) | 533 | 77.6% | 259 | 13 (5%) |
| Robustness: first-pass answers only | 2,460 | 76.7% | 1,240 | 86 (6.9%) |
Source: benchmark dataset. Constant jury of 5: Claude, GPT, Gemini, Mistral and Grok, questions where all five gave a letter. Constant jury of 6: the 533 questions Perplexity answered. First-pass view removes the 654 second-pass answers, so some questions drop below four voters; that view is easier than the full set because missing answers concentrate on hard questions.
Our headline results use the full protocol, including format-recovery passes. We also report a protocol-only robustness check; it leads to the same substantive conclusion (93.1% of unanimous answers correct without recovery, 94.0% with). Of the 1,221 unanimous questions, 71 include a second-pass answer, and so do 5 of the 73 false consensuses. Satcove reports agreement by jury size rather than treating every question as a six-model vote.
Source and Topic Results: Read Them Together
Agreement and accuracy varied sharply by source: majority accuracy was 55.2% on GPQA Diamond, 74.4% on MMLU-Pro, 84.2% on PubMedQA and 89.2% on TruthfulQA. Topics are shown only inside their source, because the same topic name mixes sets of different difficulty.
| Source | Topic | Questions | Majority accuracy | Unanimous | Unanimous wrong |
|---|---|---|---|---|---|
| GPQA Diamond | biology | 19 | small sample | 7 | small sample |
| GPQA Diamond | chemistry | 93 | 50.7% | 18 | small sample |
| GPQA Diamond | physics | 86 | 54.9% | 18 | small sample |
| MMLU-Pro | biology | 114 | 88.3% | 88 | 4 |
| MMLU-Pro | business | 115 | 62.2% | 24 | small sample |
| MMLU-Pro | chemistry | 115 | 51.1% | 20 | small sample |
| MMLU-Pro | computer science | 115 | 74.8% | 49 | 3 |
| MMLU-Pro | economics | 114 | 82.9% | 73 | 5 |
| MMLU-Pro | engineering | 114 | 73.1% | 31 | 0 |
| MMLU-Pro | health | 112 | 85.2% | 80 | 4 |
| MMLU-Pro | history | 114 | 75% | 65 | 10 |
| MMLU-Pro | law | 114 | 65.4% | 29 | small sample |
| MMLU-Pro | math | 114 | 62.5% | 15 | small sample |
| MMLU-Pro | other | 114 | 77% | 59 | 4 |
| MMLU-Pro | philosophy | 114 | 85% | 61 | 4 |
| MMLU-Pro | physics | 114 | 63.7% | 24 | small sample |
| MMLU-Pro | psychology | 114 | 87.6% | 78 | 1 |
| PubMedQA | medical | 202 | 84.2% | 127 | 9 |
| TruthfulQA (mc1) | misconceptions | 503 | 89.2% | 355 | 15 |
Source: benchmark dataset, final data. Cells with fewer than 30 questions, or fewer than 30 unanimous questions, hide the percentage (small sample). MMLU-Pro covers 1,597 of the 2,500 questions (63.9%), so it weighs heavily on overall figures. TruthfulQA and PubMedQA each form a single topic.
What This Benchmark Does Not Prove
It does not show that agreement proves truth, that Satcove's verdicts are more accurate than a single model's, or why models fail together. It measures how often a majority matched a known answer on 2,500 multiple-choice questions, and how that changed with agreement.
Agreement is not proof.
73 questions were answered identically by every model and all 73 were wrong.
Multiple choice, one letter.
The test measures option selection. It does not measure free-text reasoning or the way Satcove synthesizes an answer.
Truncated, not random.
The 2,500 questions are the first 2,500 of a 2,997-question file. MMLU-Pro supplies 1,597 of them (63.9%), so it weighs heavily on every overall figure.
Variable jury.
Five models answered 1,965 questions, six answered 533 and four answered 2. Perplexity answered a fixed 533-question sample.
Versions and recovery passes shape the scores.
654 answers came from a second pass with a different protocol per model. Four of the six model identifiers are undated aliases.
Topic results mix sources.
Physics, chemistry and biology combine GPQA Diamond and MMLU-Pro, and several cells hold fewer than 30 questions.
No reading of position bias.
Questions have between 2 and 10 options and each source distributes correct answers differently, so letter frequencies cannot be read as a model bias.
One answer per model per question.
The test cannot measure how stable an answer is across repeated runs.
No independence or contamination test.
We do not know why models agree. The public question sets may also appear in training data. Neither point was tested.
From Disagreement to Decision
A single AI answer does not tell you when to doubt it. Satcove sends a question to several models, each answering separately, measures how much they align, names where they differ and suggests what to verify before you act. The benchmark supports reading agreement as a signal; it does not test Satcove's free-text verdicts.
Illustration (not benchmark data)
STEP 1
Question
One question goes to several models.
STEP 2
Separate model answers
Each model answers on its own, with no view of the others.
STEP 3
Agreement analysis
Satcove measures how far the answers align.
STEP 4
Named disagreements
Points where models differ are listed, not averaged away.
STEP 5
Next verification step
The verdict says what to check before acting.
STEP 6
Agreement signal
You read the answer together with its level of agreement.
- Claude: Answer A
- GPT: Answer A
- Gemini: Answer B
- Mistral: Answer A
- Perplexity: Answer B
- Grok: Answer A
Named disagreement. The two dissenting models stay visible, with the point where they differ. A card says what to verify before acting. The split is not averaged away.
Related: does AI consensus prove truth, how often AI models agree, our 75-question disagreement report, AI answer reliability, Satcove Open, false consensus, agreement score and when not to use multi-AI consensus.
Methodology
Each model received every question once, with the same instruction to reply with a single option letter, in a fresh conversation. We compared the letters with the known answer and measured agreement as the share of the jury giving the majority letter. Full definitions and scripts are published.
- Date
- 22 October 2026. Calls ran the same day.
- Questions
- 2,500 multiple-choice questions with a known answer: 1,597 MMLU-Pro, 503 TruthfulQA (mc1), 202 PubMedQA, 198 GPQA Diamond. Drawn with a fixed seed within each source.
- Truncation
- The question file holds 2,997 questions. We asked the first 2,500 in file order, then stopped. This is a truncation, not a random draw: no PubMedQA question from the second batch and 97 second-batch TruthfulQA questions were asked. As a result MMLU-Pro makes up 63.9% of the questions and weighs heavily on overall figures. Within each source the draw is reproducible.
- Models and versions
- Claude claude-sonnet-4-6, GPT gpt-4o-2024-08-06, Gemini gemini-3.5-flash-lite, Mistral mistral-large-latest, Perplexity sonar (with web search; the other models had none), Grok grok-4.20-0309-non-reasoning.
- Jury
- Up to six models. Five answered 1,965 questions, six answered 533, four answered 2. Perplexity answered a fixed 533-question sample to limit cost. A question needs at least four valid answers.
- Valid answer
- A reply that starts with the option letter. Prose is never interpreted as an answer, and a missing answer is not counted as wrong.
- Majority, agreement, unanimity
- The majority is the most frequent letter; an exact tie has no majority and is excluded from majority accuracy, then counted as a failure in the second figure. Agreement is the majority's share of the jury. Unanimity means all answering models gave the same letter.
- Recovery pass
- When a first-pass reply had no usable letter (prose, truncation or an API error), we asked again for that cell only, with a protocol adapted to each model: a forced letter choice for Claude (475 answers), a longer output limit for Perplexity (86), constrained output for Gemini (85) and a plain retry for Mistral and Grok (7 and 1). In total 654 answers in the final data come from this second pass. We report first-pass-only results separately.
- Statistics
- Wilson 95% intervals. No significance tests across models, and no repeated runs.
- Not done
- No test of independence between models, no test for training-data contamination, no reading of letter-position patterns.
Provenance
Checksums let you confirm that the files you download are the ones behind this page. Run shasum -a 256 file and compare.
Show SHA-256 checksums
- Answers file
- 3ba8d9a7c5f900937f80f53a28bff6943358ed4e093e192cac06952fe4bc6024
- Source workbook
- 14c33d4b5730b70f0e1c0f7c17caa2bfe9084ce1f761b45d40db027d12080ced
- Rights
- All rights reserved. Aggregate results and analysis artifacts are provided for verification; question texts are not redistributed. We could not confirm the licences of the source question sets (MMLU-Pro, TruthfulQA, PubMedQA, GPQA), so we publish option letters and ids only.
- How to cite
- Satcove Research, "AI Consensus Benchmark", 22 October 2026, satcove.com/research/ai-consensus-benchmark.
Download the Data and Scripts
Every figure on this page can be recomputed from the answers file. The files below include the claims list, the second-pass cells, the analysis script and checksums. No question text, prompt, key or user data is included.
| File | Contents | Size |
|---|---|---|
| ai-consensus-benchmark-2026-10-22-answers.csv | Answers by question: every model's letter, majority, agreement (2,500 rows, no question text) | 150 KB |
| claims.csv | Every claim used on this page, with its source and calculation | 6 KB |
| recovered_cells.csv | The 654 answers that came from the second pass | 34 KB |
| metrics_no_recovery.json | Metrics from first-pass answers only | 6 KB |
| recovery_impact.csv | First-pass vs. second-pass accuracy by model | 1 KB |
| jury_sensitivity.csv | Results by jury size and constant jury | 1 KB |
| equal_footprint.csv | Models compared on identical questions | 2 KB |
| source_by_topic.csv | Source × topic table with small-sample flags | 2 KB |
| definitions.md | Definitions: jury, majority, unanimity, recovery, false consensus | 3 KB |
| v1_analysis.py | Analysis script (pandas) | 9 KB |
| build_recovered_cells.py | Script that lists second-pass cells (reads private run logs) | 2 KB |
| SHA256SUMS.txt | SHA-256 checksums of every file | 1 KB |
Open each file directly. SHA-256 values are also in SHA256SUMS.txt.
Frequently Asked Questions
Short answers on what agreement between AI models can and cannot tell you, based on this benchmark.
Does agreement between AI models mean the answer is correct?
No. In our benchmark, unanimous answers were correct 94.0% of the time (1,148 of 1,221 questions), so agreement is a strong signal, but 73 unanimous answers were wrong. Agreement shows that models converged, not that anyone checked the facts. Models can share the same blind spot. Treat agreement as a reason for more confidence, and keep verifying anything with real consequences, such as a medical, legal or financial decision.
How often are unanimous AI answers wrong?
In our test, 73 of 1,221 unanimous questions were unanimously wrong, or 6.0%. The rate differed by source: 4.2% for TruthfulQA, 6.3% for MMLU-Pro, 7.1% for PubMedQA and 11.6% for GPQA Diamond, although GPQA rests on only 43 unanimous questions. This is the rate on these multiple-choice questions, with up to six models answering (five on most questions). It is not a general error rate for AI.
What does low agreement between AI models mean?
It means the models split. When agreement fell below 60%, the majority answer was correct only 33.5% of the time (194 questions with a majority; 197 more ended in an exact tie). On those questions, no single answer was a reliable guide. Low agreement does not say which model is right. It says the question is contested, hard or ambiguous, and that the answer needs checking against a source before you rely on it.
Can multi-AI consensus replace fact-checking?
No. Consensus tells you where to look, not what is true. In our benchmark the majority answer was correct 77.1% of the time on the 2,303 questions where one existed, and 71.0% across all 2,500 questions when ties count as failures. Claude alone scored 77.5% on the same 2,303 questions. Agreement is useful for triage: high agreement lowers the priority of a check and disagreement raises it. Facts that matter still need a primary source.
Why can ChatGPT, Claude and Gemini make the same mistake?
We did not test the cause, so this is a hypothesis, not a finding. Plausible reasons include overlapping training data, similar training methods, misconceptions common in the text the models learn from, and question wording that pulls toward the same wrong option. Our data only shows that it happens: on 73 questions every answering model chose the same wrong answer. We tested GPT-4o, Claude Sonnet 4.6 and Gemini 3.5 Flash-Lite through their APIs, not the consumer apps.
When should you verify an AI answer?
Verify when models disagree, when the stakes are high, and when the answer rests on one claim you cannot easily judge, such as a date, a dose, a legal citation or a price. In our test, majority accuracy fell to 56.2% for clear majorities (60-79% agreement) and 33.5% below 60%. Even unanimous answers were wrong 73 times. Checking a primary source costs little compared with acting on a shared error.
What is a false consensus in multi-AI systems?
A false consensus is a question where every model that answered gave the same answer and that answer was wrong. We found 73 among 2,500 questions: 44 in MMLU-Pro, 15 in TruthfulQA, 9 in PubMedQA and 5 in GPQA Diamond. They matter because agreement looks like confirmation. A system that reports only a majority hides these cases. The safeguard is to read the agreement level together with the stakes, and to check what matters against an external source.
How does Satcove use disagreement between AI models?
Satcove sends one question to several models, each answering separately, then shows an agreement score and names the points where the models differ, with a next step to verify. When models split, the verdict says so instead of averaging the differences away. This benchmark tested simple letter agreement on multiple-choice questions, not Satcove's free-text synthesis. It supports reading agreement as a signal; it does not measure the accuracy of a Satcove verdict.
See where the models agree, where they split and what to verify.
Satcove shows an agreement score and names the disagreements for your own question. Agreement is a signal, so the stakes still decide how much checking is enough.