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Jev Calibration Audit

An unaffiliated, API-only audit of Jev calibration built on roughly 7,000 public HTTP calls, covering abstention, Korean, probabilistic coherence, option order, question interference, caching and latency, with a drift ledger.

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Python
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MIT
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Author
jujumilk3
Last verified
Oct 2026

Independent API-only calibration audit of TypeSafe AI's Jev decision model

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Updated Sep 2026

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About this project

An independent, API-only audit of the calibration of TypeSafe AI's Jev, a "System One" decision model that answers pre-defined questions over a text state with probability distributions instead of generated text. Not affiliated with TypeSafe AI. No model weights, no fine-tuning, no distillation — every number here comes from public HTTP calls and public datasets.

Quoted from the project's README. Read the full README.

Highlights

  • Remove the unknown option and accuracy on unanswerable items drops from 0.950 to 0.000 while the stereotype rate rises from 0.03 to 0.79.
  • Option-order bias came back as none: mean shift 0.005, zero argmax flips in 400 trials, and 16 bundled questions shifted confidence 0.008.
  • The probability is not a property of the judgement: complements summed to 0.71-1.42, and Noul vs Choice differed by 0.125.
  • Method notes are as load-bearing as the numbers: report ECE against a noise floor rather than zero, since a perfect model still scores about 0.045 at n=60.

Watch out

This is one independent researcher publishing against a model he does not control, with no affiliation to TypeSafe, and every figure comes from public HTTP calls rather than weights. The README's opening complaint is precisely that published measurements disagree and that none report confidence intervals, so read the bootstrap CIs in FINDINGS.md alongside the headline numbers. Model aliases move, which is why every response's model field is logged and why the drift ledger has to be run on a schedule to be useful at all, and why the confidence field is undocumented and all metrics are computed from probabilities instead. The state-blind control is the part most benchmarks skip: shown the options with the question removed, the model still scores 0.38-0.46 against a chance rate near 0.15. Datasets are not redistributed here, only results. Copy reviewed against the repository README on 2026-10-04, not from running it.

Questions about this entry

Short answers drawn from the linked project or page.

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From the Jev guides

Original write-ups on what this entry is for.

Most Jev accuracy problems are state problems. What belongs in a state, what is a pre-made judgment to leave out, and why naming the slice you ask about matters more than the wording.
Jev Practices & Patterns#state#design#primitives
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A Noul returns one number and no separate confidence. How to read the value, pin its boundary with criteria, split compound questions, and set a per-action threshold that matches the cost of being wrong.
Jev Practices & Patterns#noul#primitives#confidence
Read article
A Score is a weighted position, not a ruler. Why the number can land between levels, why levels are judged separately, and how to combine several atomic scores in code instead of one crowded rubric.
Jev Practices & Patterns#score#primitives#scoring
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