Introducing
BEM-2
Small biomedical models that identify a paper’s study design, and how strongly its sentences claim causation.
What kind of study, and how strong a claim.
BEM-2, the Biomedical Epistemic Model, is our second-generation family of compact models for reading biomedical research. Given an abstract, BEM-2 Examine and its smaller sibling, Examine Mini, identify the paper’s study design, from meta-analysis to case report, rate how strongly each sentence claims cause and effect, and flag statements that may claim more than the design can support. BEM-2 Compose writes abstracts for a requested study design, trained with our Epistemic Warrant Optimization to keep its claims within what that design supports. On 20,000 papers first indexed in 2026, BEM-2 Examine’s study-design labels agree with PubMed’s 98.1% of the time. At study-design classification, Examine Mini performs at the level of leading frontier models and grades 200 abstracts in 7.7 seconds on an ordinary laptop CPU. Press-release language is harder for Examine, and there the frontier models do better.
At work.
An agent searches the research, hands BEM-2 the 200 papers it found, and has every study design back in 0.06 seconds.
- of Examine’s study-design labels agree with PubMed’s, on 20,000 new papers
- 98.1%
- to grade 200 abstracts on a laptop CPU, with Examine Mini
- 7.7 s
- faster for Examine Mini than BEM-1’s fastest configuration, on the same laptop
- 3.4×
- smaller than Examine: Examine Mini, the smallest of the family
- 2.7×

The family.
BEM-2 Examine
ReadsReports a paper’s study design with a calibrated confidence, the claim strength of each sentence, and Warrant Check flags.
BEM-2 Examine Mini
Reads, fast · about 2.7× smaller than ExamineThe same reports from a smaller, faster model that runs on an ordinary laptop CPU.
BEM-2 Compose
Writes · about 3.2× the size of ExamineWrites abstracts for a requested study design, aiming to keep its claims within what that design supports.
Benchmarks
Measured by Essarion on data BEM-2 never saw in training. Blue marks the best result on each test; grey marks BEM-2’s where another model did better.
| Test | BEM-2 | BEM-1 | GPT-6-Astra | GPT-6.1-Sol | GPT-6-Luna | Claude Opus 5.5 | Claude Sonnet 5.5 | Claude Haiku 5.5 | Claude Fable 5.1 | Qwen3-32B, thinking | OpenAI gpt-oss-20b |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Reading · BEM-2 Examine and Examine Mini | |||||||||||
| Study design, 300 papersAccuracy vs PubMed’s labels | 98.3%Examine Mini | 97.0%Examine | 92.0% | 92.0% | 92.7% | 93.0% | 93.3% | 92.7% | 94.2% | – | 93.0% |
| Study design, 300 papersAccuracy; disputed reviews count either way | 98.7%Examine Mini | 97.3%Examine | 97.3% | 97.3% | 96.7% | 97.7% | 98.3% | 97.7% | 97.3% | – | 93.7% |
| Study design, 2,000 papersAccuracy vs PubMed’s labels | 98.35%Examine97.85%Examine Mini | 97.35%Examine | – | – | – | – | – | – | – | – | 92.50% |
| Study design, 20,000 papersAccuracy vs PubMed’s labels | 98.13%Examine97.89%Examine Mini | 97.59%Examine | – | – | – | – | – | – | – | – | – |
| Seconds per 200 abstracts, one GPULower is better | 0.06Examine Mini | 0.56Examine | hosted | hosted | hosted | hosted | hosted | hosted | hosted | – | 4.5 |
| Cost per 1,000 abstracts, study designUS dollars; lower is better | $0.0001Examine Mini$0.0012Examine | – | $7.87 | $1.57 | $0.08 | $3.15 | $1.57 | $0.08 | $7.87 | – | – |
| Claim strength, 300 abstract sentencesMacro-F1, Yu et al. 2019 | 68.5Examine | 50.3Examine | 80.9 | 77.2 | 66.7 | 72.9 | 71.2 | 72.8 | 80.2 | 70.3 | 69.4 |
| Claim strength, 2,137 abstract sentencesMacro-F1, Yu et al. 2019 | 71.5Examine | 49.1Examine | 83.0 | 81.1 | 66.0 | 86.7 | 76.5 | 76.5 | 82.4 | 73.1 | 71.4 |
| Claim strength, 300 press-release sentencesMacro-F1, Yu et al. 2020 | 68.3Examine | 37.8Examine | 85.1 | 85.3 | 69.6 | 81.3 | 75.5 | 77.3 | 80.4 | 71.4 | 72.3 |
| Claim strength, 2,074 press-release sentencesMacro-F1, Yu et al. 2020 | 66.0Examine | 38.7Examine | 81.2 | 81.2 | 70.2 | 80.7 | 75.5 | 77.8 | 80.1 | 74.2 | 73.1 |
| Press-release exaggeration, 150 pairsMacro-F1, Wright & Augenstein 2021 | 46.2Examine | 37.9Examine | 72.3 | 71.5 | 65.5 | 73.0 | 74.4 | 73.4 | 72.5 | 61.4 | 65.3 |
| Writing · BEM-2 Compose | |||||||||||
| Overclaiming when writingShare of texts; lower is better | 46.7%Compose | 50.0%Compose | 13.3% | – | 20.0% | 60.0% | 46.7% | 30.0% | 53.3% | – | – |
On the full 563-pair exaggeration test, Examine scores 49.0, against 52.3–66.5 for the open models and a published best of 61.11.
Study design
The first thing a careful reader asks of a paper is what kind of study it is. We tested Examine and Examine Mini on papers first indexed in PubMed in 2026, after their training data was collected, and scored their labels against PubMed’s own.
Against seven frontier models given the same instructions, BEM-2 Examine Mini sits at the top of a close group. Reviews of animal or cell research are the one category in dispute: the instructions call them preclinical, PubMed often calls them reviews. Counted either way, every frontier model is within about two points of Examine Mini.
Study design, against frontier models
Accuracy on 300 papers first indexed in 2026. Reviews of animal or cell research count as right whether labelled preclinical or review.
Against open models run on the same 2,000 papers and the same GPU, the gap is wider. Examine leads the strongest of them, Mistral-Small-3.2-24B, by 3.5 points, and Examine Mini leads it by 3.0. BEM-1 Examine leads them too, which says most of that lead comes from specialising on the task.
Study design, against open models
Accuracy vs PubMed’s labels on 2,000 papers first indexed in 2026, same papers and same GPU for every model.
Speed
Examine Mini grades 200 abstracts in 7.7 seconds on an ordinary laptop CPU, 3.4 times faster than BEM-1’s fastest configuration, with no GPU and no data leaving the machine. Examine, the larger model, takes 21.7 seconds on the same laptop. On one GPU, Examine Mini takes 0.06 seconds, against 0.56 for BEM-1 Examine, and is about 51 times faster than the fastest open model we ran.
On a laptop
Seconds to grade 200 abstracts on a laptop CPU (Intel i7-1165G7), no GPU. Lower is better.
On one GPU
Seconds to grade 200 abstracts on the same workstation GPU, open models at their default generation settings. Lower is better.
Cost
Reading 1,000 abstracts for study design costs about a hundredth of a cent with Examine Mini, and about a tenth of a cent with Examine. The frontier models in the same test cost between 8 cents and $7.87 for the same thousand abstracts.
Accuracy against cost
Study-design accuracy on 300 papers against the cost of reading 1,000 abstracts. Higher and further left is better.
| Model | Cost per 1,000 abstracts | Accuracy |
|---|---|---|
| BEM-2 Examine Mini | $0.0001 | 98.7% |
| BEM-2 Examine | $0.0012 | 98.3% |
| Claude Haiku 5.5 | $0.08 | 97.7% |
| GPT-6-Luna | $0.08 | 96.7% |
| Claude Sonnet 5.5 | $1.57 | 98.3% |
| GPT-6.1-Sol | $1.57 | 97.3% |
| Claude Opus 5.5 | $3.15 | 97.7% |
| GPT-6-Astra | $7.87 | 97.3% |
| Claude Fable 5.1 | $7.87 | 97.3% |
Test size
Examine is the more accurate reader, and it shows once a test is large enough to tell. It leads Examine Mini by about a quarter of a point on 20,000 papers, on 95,334 and on a million, where that is over 2,600 more papers labelled correctly. The 300-paper test is too small to show it. A single paper there is worth a third of a point and a score can land a point and a half either side of where it settles, so Examine can come out behind, as it does by one paper.
Accuracy by test size
Accuracy vs PubMed’s labels at each test size, with the range a test that size is expected to give Examine on new 2026 papers. The million-paper test adds 904,666 older papers BEM-2 never saw in training. The two largest tests ran both models in fast mode.
| Model | Papers in the test | Accuracy |
|---|---|---|
| BEM-2 Examine | 300 | 98.0% |
| BEM-2 Examine | 2,000 | 98.35% |
| BEM-2 Examine | 20,000 | 98.13% |
| BEM-2 Examine | 95,334 | 98.13% |
| BEM-2 Examine | 1,000,000 | 97.80% |
| BEM-2 Examine Mini | 300 | 98.3% |
| BEM-2 Examine Mini | 2,000 | 97.85% |
| BEM-2 Examine Mini | 20,000 | 97.89% |
| BEM-2 Examine Mini | 95,334 | 97.89% |
| BEM-2 Examine Mini | 1,000,000 | 97.54% |
Epistemic Warrant Optimization
A model that writes about research should not claim more than the research shows. BEM-2 Compose was trained with Epistemic Warrant Optimization (EWO), our method for teaching a writer to keep each claim within what its study design supports.
Against an otherwise identically trained version without it, blind judges found overclaiming in 27% of Compose’s texts rather than 44%, and in 37% rather than 48% when fresh judges read the same texts again. Most of the gain is in case reports and reviews; observational texts still make causal claims about half the time. Part of it comes from more cautious writing. Judges also recognised the intended study design less often with EWO, 55% against 71%.
Set against BEM-1, Compose now writes for the requested design far more reliably: judges could tell which design a text was written for 55% of the time, against 23%. Open and frontier models still do this better.
Less overclaiming, with EWO
Share of BEM-2 Compose texts that claimed more than their study design supports, against an otherwise identically trained version without Epistemic Warrant Optimization. 600 texts, judged blind. Lower is better.
Writing for the requested design
How often blind judges could tell which study design a Compose text was written for. 450 texts each. Higher is better; still below open and frontier models.
Against frontier writers given ten clinical topics to write about, Compose sits in the middle of the range. It overclaimed more often than four of the seven, significantly so only against GPT-6-Astra, and at a rate similar to Claude Sonnet 5.5.
Overclaiming, against every writer
Share of texts that claimed more than their study design supports, judged blind by AI judges from two model families; 30 texts per writer, 60 for BEM-2 Compose. Lower is better.
Claim strength
Examine also rates how strongly each sentence claims cause and effect, from no relationship to direct causation, following the Sumner et al. (2014) coding. This is where the frontier models are stronger. On sentences from scientific abstracts Examine is ahead of GPT-6-Luna and of the open models that do not reason first, and behind the rest. It is a long way ahead of BEM-1 Examine, which scored 50.3 on the same 300 sentences.
Claim strength, in scientific abstracts
Macro-F1 on 300 sentences from scientific abstracts (Yu et al. 2019). Higher is better.
Press releases are harder. On 2,074 press-release sentences Examine trails every frontier model and every open model we tested except BioMistral-7B. It was built for research text, and this is where that shows.
Claim strength, in press releases
Macro-F1 on 2,074 press-release sentences (Yu et al. 2020). BEM-2 is built for research text, and this is its weaker ground.
Warrant Check
Warrant Check compares a sentence’s claim with what its study design can support. On 1,050 texts written by seven different models, its score separates overclaiming texts from careful ones with an AUC of 0.73, against blind judges. It catches most overclaims and also flags many careful texts, so it works as a first pass that points a person at the sentences worth checking. Detecting exaggeration in press releases remains Examine’s weakest area.
Exaggeration, in press releases
Macro-F1 at telling whether a press release claims more than its paper, on 150 pairs (Wright & Augenstein 2021). Higher is better.
BEM-2 is available in Essarion Science.
The models are private. BEM-2 succeeds BEM-1, our first family of biomedical models.
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