the short answer
In Jev, probability belongs to an answer outcome. Choice returns one probability per option, Score returns one per rubric level, and Noul returns the probability of yes. Choice and Score also return confidence, which summarizes how concentrated their distribution is. Confidence does not prove correctness, data sufficiency or permission to act, and Noul has no separate confidence field.
- Choice probability
- Relative probability for each listed option
- Score probability
- Probability for each ordered rubric level
- Noul
- Probability of yes; no separate confidence
- Confidence
- Distribution concentration for Choice and Score
Read the Fields by Primitive
A Choice can be low-confidence because several acceptable alternatives split the distribution. That does not always make the decision unusable: selecting a harmless color theme may tolerate ambiguity, while routing an irreversible action should not. Confidence must be interpreted with the action and candidate set.
| Primitive | Probability field | Confidence field |
|---|---|---|
| Choice | Map from option name to probability | How concentrated the options are |
| Score | Map from rubric level to probability | How concentrated the levels are |
| Noul | One yes probability from 0 to 1 | None |
Probability, Concentration and Correctness Answer Different Questions
Only the third question establishes calibration, and it cannot be answered from one response. A concentrated distribution describes the model output for the supplied state and answer set. It does not validate the state, criteria, model version or application threshold.
Keep the complete distribution even when the UI displays one answer. The runner-up probability and the gap between the top two candidates can explain why two winning labels with the same top probability have different ambiguity.
| Question | Relevant evidence | Example |
|---|---|---|
| Which outcome does the model favor? | Probability attached to each answer | billing: 0.55 leads technical: 0.45 |
| How divided is this distribution? | Choice or Score confidence plus the complete distribution | 0.51 / 0.49 is more divided than 0.98 / 0.02 |
| How often is the model right at this value? | Held-out labels and outcomes from comparable cases | Predictions near 0.8 are correct about 80% of the time |
A Noul Value Is Not Intensity
A Noul of 0.5 means yes and no have similar modeled probability. It does not mean the condition is present at medium strength. If the application needs severity, define an ordered Score rubric or separate semantic dimensions. If it needs several labels that can coexist, ask several Nouls.
Three Examples Show Why the Fields Are Different
The word “confidence” is tempting to read as a universal trust score. In TypeSafe’s interface it summarizes concentration for a particular Choice or Score distribution. It does not know whether the state omitted decisive evidence, whether criteria overlap, or whether the question belongs in the model at all.
| Result | What it says | What it does not say |
|---|---|---|
Noul 0.82 | Yes has modeled probability 0.82 for that question | The condition is 82% intense |
Choice billing: 0.55, technical: 0.45 | Billing narrowly leads the supplied alternatives | Billing is certainly correct |
| Score concentrated on level 2 | One rubric level dominates the distribution | The real-world quantity literally equals 2 |
Worked Choice Example: The Same Winner Can Imply Different Risk
Do not compare 0.80 across the second and third rows as if the experiments were identical. Adding, removing or rewriting candidates changes the decision being asked. Store the candidate-set version with the result and recalibrate after taxonomy changes.
If labels may coexist—billing and account security, for example—one Choice forces competition. Separate Nouls may better represent the task. The Choice-versus-Noul guide works through that modeling decision.
| Distribution | Winner | Operational reading |
|---|---|---|
| billing 0.51, technical 0.49 | billing | Near tie; route to review if a wrong queue is costly |
| billing 0.80, technical 0.10, account 0.10 | billing | Concentrated among the supplied options; still validate no-match coverage |
| billing 0.80, technical 0.20 | billing | Same top probability, but not the same candidate set or question |
| billing 0.98, technical 0.01, other 0.01 | billing | Very concentrated; still can be confidently wrong |
Worked Score Example: Preserve the Distribution Behind the Average
The expected score is a useful summary for ranking or monitoring, but it hides shape. A distribution split between routine and critical can have the same average as one concentrated on time-sensitive. Store and inspect the level probabilities, not only the weighted value.
The numeric spacing—0, 1 and 2—is chosen by the application. It assumes adjacent rubric levels are equally spaced for the calculation. Jev is not measuring minutes or dollars, and the Score guide explains why level wording must carry the semantics.
levels = {"routine": 0, "time_sensitive": 1, "critical": 2}
distribution = {"routine": 0.10, "time_sensitive": 0.65, "critical": 0.25}
expected_score = sum(
levels[level] * probability
for level, probability in distribution.items()
)
# 1.15 on this application-defined ordinal scaleA Concentrated Wrong Answer Can Still Have High Confidence
Suppose a routing Choice contains only billing and technical, but the request actually needs an account-security team. Jev can strongly prefer billing over technical because it must compare the supplied candidates. The distribution may be concentrated even though the candidate set is wrong. Add a no-match path or separate fit test.
The same issue appears with missing state. If the relevant tool result was never supplied, a clean-looking distribution does not recover it. Validate evidence completeness before interpreting model numbers. See Choice and state design.
Turn Distributions into Actions Carefully
Thresholds belong to application code and depend on consequences. Fit them against representative labeled outcomes, then report both coverage and errors. A high threshold may reduce false actions while sending more traffic to review. A model update, question rewrite or population shift can invalidate the old operating point.
- Log raw distributions instead of only the winning label.
- Do not compare confidence across unrelated questions as if it were one quality score.
- Do not use confidence as authorization for a protected action.
- Keep a review or fallback path for uncertainty and service failure.
Store Model Output Separately from the Application Decision
This is an application record, not the TypeSafe response schema. Keeping raw model fields separate from derived action fields permits threshold replay and shows whether a later change came from Jev, the question or policy code. Never overwrite the original answer with review or fail; those are application states.
{
"primitive": "choice",
"answer": "billing",
"distribution": {
"billing": 0.55,
"technical": 0.45
},
"confidence": "<native Jev value>",
"question_version": "support-route-v4",
"model_resolved": "jev-1.13.0",
"threshold_version": "support-route-bands-v2",
"application_action": "human_review"
}Calibration Connects Probabilities to Observed Outcomes
To test a Noul probability, group many comparable predictions into ranges and compare each range with observed yes rates. If cases near 0.8 are positive only half the time, that deployment is overconfident even though individual answers may look plausible. Choice and Score need equivalent task-specific analysis of their distributions.
Calibration belongs to the full evaluator: model, question, criteria, state projection and traffic. Changing any part can invalidate the old threshold. The calibration guide provides reliability diagrams and scoring metrics; thresholds converts validated probabilities into actions.
Use Different Diagnostics for Different Failure Claims
scikit-learn’s calibration documentation illustrates reliability diagrams and proper scoring rules, but those methods must be applied to the exact Jev question and target population. A good Brier score can combine calibration and discrimination effects; inspect the reliability curve and task errors rather than treating one scalar as the whole evaluation.
NIST’s measurement guidance emphasizes documenting metrics, uncertainty and limitations. Record denominators and confidence intervals, especially for rare high-consequence slices. The evaluate-the-evaluator guide turns these diagnostics into release evidence.
| Claim | Diagnostic | Do not substitute |
|---|---|---|
| Probabilities track observed frequency | Reliability bins, Brier score or log loss | Average confidence |
| Winning labels are correct | Confusion matrix and per-class precision/recall | Calibration alone |
| Automated cases are safe enough | Selective risk at stated coverage | Accuracy on all cases |
| Repeated calls are stable | Flip rate and within-case distribution movement | One successful request |
| A release did not regress | Paired frozen-set and slice comparison | Similar aggregate mean |
Monitor the Operating Point, Not a Confidence Average
A higher average confidence after a release is not automatically an improvement; the system may simply have become more concentrated while accuracy stayed flat or worsened. Confirm changes with labels or outcomes and replay the old and new instruments on the same evidence. The drift guide defines that workflow.
- Probability and confidence distributions by criterion, answer and important slice.
- Automation, review, refusal and unscorable coverage with stable denominators.
- Delayed errors, overrides and downstream outcomes for every action band.
- Resolved model, provider, question, candidate-set and projection versions.
- Missing evidence, invalid responses, retries and latency separately from semantic uncertainty.
FAQ
Does high Jev confidence mean the answer is correct?
No. It means the Choice or Score distribution is concentrated. Accuracy and calibration still have to be measured on the target task.
Why does Noul not return confidence?
Noul directly returns the probability of the yes outcome. TypeSafe does not define a separate Noul confidence field.
Can I use 0.8 as a universal Jev threshold?
No. Choose a threshold from labeled target data and the cost of each mistake. Different actions and questions need different operating points.
Are Choice probability and equivalent Noul probability the same?
Do not assume so. TypeSafe documents that separate formulations and primitives need not satisfy expected arithmetic identities. Evaluate the exact question you deploy.
Sources
Checked against the sources below on September 22, 2026. Model versions, prices and limits change.
- TypeSafe AI docs: Confidence
- TypeSafe AI docs: Primitives
- TypeSafe AI docs: AI primer and RLCD
- TypeSafe AI docs: Jev 1.13 jaggedness
- scikit-learn: Probability calibration and reliability diagrams
- NIST AI RMF: Measure function