Eval metrics lab
Mastery: ship checklist
A second person can reproduce candidate prompt beats baseline on groundedness by ≥ 0.03 without latency regression > 10% from a clean checkout and name the owner for EVAL-LEAK-308.
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Clean-room demo
From a fresh clone/directory, run the commands that prove candidate prompt beats baseline on groundedness by ≥ 0.03 without latency regression > 10%. A second person plays ML engineer gating a prompt change before Friday release and follows your script without coaching. The demo includes limitations: what offline+online eval harness for grounded support answers still will not do.
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Evidence pack
Bundle: contract snippet, passing tests, metric snapshot for groundedness, citation_precision, p95_latency_ms, security negative probe, rollback note, owner name. Reference EVAL-LEAK-308 as the drill you rehearsed. If any item is missing, the ship gate fails even if the happy path dazzles.
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Implementation artifact
python -m eval.run --gold v12 --candidate prompts/p17.md --baseline prompts/p16.md --fail-under 0.88
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Ownership and next review
For Eval metrics lab, name the human who gets paged, the review date for thresholds, and the condition that triggers reevaluation. Endpoint python -m eval.run --gold v12 remains the production surface you operate for offline+online eval harness for grounded support answers — not a slide. Keep EVAL-LEAK-308 in the handoff template so the next owner inherits the drill.
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Stage depth
After the peer demo, schedule the next threshold review date. File a short changelog that mentions EVAL-LEAK-308 and the control that addresses it. Archive the evidence pack where your team already stores launch records. Resist rewriting everything “for real production” in one weekend — operate this slice until the metrics bore you, then widen. Final self-check: if telemetry vanished, would you still know to hold? If yes, you learned the operating posture this lane teaches.
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Field notes for `eval-metrics-lab` / `mastery-ship`
Trim the demo script until every command is necessary. Record a peer signature line: name, date UTC, pass/fail. File known limitations as bullets, not apologies. Link the evidence pack from the README. Schedule the next game day on a calendar, even if it is solo. Archive the branch tag or release digest you actually shipped. In this chapter the product is offline+online eval harness for grounded support answers, the human stakeholder is ML engineer gating a prompt change before Friday release, and the incident id you design against is EVAL-LEAK-308. Re-state the oracle in your notes — candidate prompt beats baseline on groundedness by ≥ 0.03 without latency regression > 10% — and keep the invariant visible: release needs groundedness ≥ 0.88 and latency p95 ≤ 2.0s on fixed gold set v12. Track groundedness, citation_precision, p95_latency_ms as the scoreboard. Surface under change control: python -m eval.run --gold v12. If you only have forty minutes, finish the fixture for eval set leaked into few-shot examples — scores look perfect, prod drops before polishing UI. Promotion language stays ternary: promote, hold, or roll back based on evidence, not hope.
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Why this matters
Draft a two-minute demo script that proves candidate prompt beats baseline on groundedness by ≥ 0.03 without latency regression > 10% from a clean directory. Include the failure rehearsal for eval set leaked into few-shot examples — scores look perfect, prod drops and the rollback/owner line. If the script needs tribal knowledge, the lab is not shipped.
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