Trace a worked example

Scenario: For extracting a country code, use a strict schema and low temperature. For naming a gardening app, sample 20 candidates at a moderate temperature, deduplicate them, then score memorability and trademark risk.

Write the trace as numbered state transitions, not a polished story:

1. Capture the input, version, identity, and assumptions.
2. Apply the mechanism: For logits z and temperature T, sampling uses softmax(z/T). When T is below 1, logit differences become larger and the distribution concentrates. Above 1, differences shrink and less-likely tokens receive more probability. At T approaching zero, implementations approximate greedy selection. Seeds and provider infrastructure may still prevent exact reproducibility.
3. Record the relevant controls: temperature; top-p; top-k where available; random seed; number of candidates; prompt constraints; maximum tokens; and a separate selection or ranking step.
4. Calculate or inspect the intermediate signal: with logits [2,1], T=1 gives probabilities about [0.73,0.27]; T=0.5 gives [0.88,0.12], showing concentration rather than a linear creativity dial.
5. Compare the result with a baseline and an acceptance threshold.
6. Store enough evidence to reproduce the decision without storing unnecessary sensitive content.

Now perturb the trace. Change one input to a long, stale, ambiguous, or unauthorized case. A robust design should either continue within its contract or abstain visibly. Silent degradation is worse than a clear refusal because downstream systems may interpret fluent output as verified output.

For extracting a country code, use a strict schema and low temperature. For naming a gardening app, sample 20 candidates at a moderate temperature, deduplicate them, then score memorability and trademark risk.

The worked number is with logits [2,1], T=1 gives probabilities about [0.73,0.27]; T=0.5 gives [0.88,0.12], showing concentration rather than a linear creativity dial. State the unit and denominator whenever you report it. A percentage without a denominator can conceal a tiny sample; a latency without a percentile can conceal slow users; a similarity score without a labeled task can conceal irrelevant neighbors. Compare the observed value with a threshold chosen before seeing the final test result.

Now test the tempting shortcut. Suppose the team optimizes only the most visible metric. The result may look better while the system becomes less trustworthy. The reason is concrete: Low temperature improves consistency but can repeat bland or systematically wrong answers. High temperature produces diverse candidates but raises variance and review cost. Combining high temperature with broad top-p can make outputs erratic; tune one sampling control at a time. This is why the decision record must include both the intended gain and the tolerated regression. If the tolerated regression is unknown, the change is not ready for a consequential workflow.

• Prefer a measured baseline over a persuasive demo.
• Keep versions, inputs, and thresholds reproducible.
• Separate syntactic success from semantic correctness and authorization.
• Escalate or abstain when evidence falls outside the contract.
• Re-evaluate when data, traffic, models, providers, or user goals change.

These rules turn the topic into an engineering decision rather than a slogan. They also make disagreement productive: another person can challenge the assumptions, rerun the evaluation, and reach a documented conclusion.

The trace used one set of assumptions. Change one quantity by a realistic amount while holding the others fixed, then recompute the result. Next change a categorical assumption: model version, tenant, language, traffic shape, data freshness, or permission level. Mark which steps remain valid and which must be repeated. This is a stronger test than narrating the happy path because it reveals hidden coupling. Preserve the original and perturbed traces side by side, including intermediate values, so a reviewer can locate the first point at which their behavior diverges.