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FIELD GUIDE 09 · Expert

Test the behavior, not the impressive answer.

Build a small evaluation set, define observable checks, and compare changes without hiding critical failures.

3 min read · Plus practice · Editorial update: 23 October 2026
KNOW FIRSTEvaluation & risk →
YOUR DOMAINEvaluation, Security & Governance
GO NEXTAI agents & permissions →
What you will be able to do

Create an evaluation record with cases, expected behavior, separate scores, and a justified release decision.

Define what must happen

An evaluation starts with a task and a checkable outcome. First, describe what the system should do and what it must never do.

Observable checks turn vague goals into evidence. Replace “helpful answer” with “states the current deadline and identifies the source passage.”

Task success may depend on an action outside the answer. Therefore, inspect the resulting record when a system claims it completed a change.

Build a useful case set

Representative cases should reflect the work you expect. Include ordinary requests, missing evidence, conflicting inputs, and actions outside the system’s authority.

Repeated trials help expose variable behavior. Run a case more than once when inconsistent answers would affect your decision.

A held-out set contains examples you did not use while adjusting the system. Otherwise, improvements may reflect familiarity with your test questions.

Write a rubric before testing

Separate dimensions make trade-offs visible. Score source support, required content, appropriate uncertainty, and permissions independently.

Critical checks must not disappear inside an average. Define which failures block the proposed use before seeing the results.

Review disagreements are useful evidence about the rubric itself. Ask two reviewers to score several examples, then clarify ambiguous criteria.

Compare two fictional candidates

A fictional assistant drafts equipment-policy answers for staff. The following invented results describe ten fixed questions tested once per candidate.

Candidate B improves source support from eight answers to nine. However, it also exposes restricted material in one answer.

The decision is to reject B for this release under the stated confidentiality gate. A higher content score cannot override that failure.

Illustrative comparison: ten questions, one trial each
CheckCandidate ACandidate BInterpretation
Supported answer8 / 109 / 10Content improved on this sample
Required details9 / 109 / 10No observed change
Restricted-data disclosure0 / 101 / 10B fails the critical gate
Release conclusionMore testing neededDo not releaseNeither result proves general safety

Record enough to reproduce

An evaluation record includes the case ID, input, expected behavior, and observed result. Also record the prompt, model, source version, and application configuration.

A failure note should identify the actual mismatch. “Answered from retired policy” is more useful than “bad answer” when deciding what to repair.

The comparison boundary must remain clear. Ten teaching examples can reveal defects, but cannot establish a reliable real-world failure rate.

Practice: defend the release decision

Your exercise adds two questions involving missing evidence and two involving restricted information. Write the expected behavior before drafting any answers.

Your evidence packet should contain a rubric, case records, and one short recommendation. Use fictional material and test manually if you have no AI service.

A strong response distinguishes observed improvement from release readiness. Explain which failure blocks release and which uncertainty requires more testing.

Compare with the worked answer

Worked answer: Reject candidate B for the stated use. Investigate the disclosure, repair the access boundary, and retest related cases. Keep the content improvement as a separate finding. Candidate A still needs broader evidence before approval.

What to carry forward

Create an evaluation record with cases, expected behavior, separate scores, and a justified release decision.

Show your reasoning with the exercise above. Keep the evidence, the decision, and the remaining uncertainty together.

Useful terms for this lesson

EvaluationRubricHuman ReviewLeast Privilege

Sources & further reading

Anthropic: Demystifying evals for AI agents ↗

AI Competence: Learning routes ↗

The practical examples and exercises on this page are illustrative. Source links provide background; they do not certify the exercises or endorse this hub.

Apply this idea to a worked case.

The agent that passed the wrong test →