Study · Pack

eval-harness-101

Product eval harness · ~6 sit-down days · 30–60 min/day

Explain and run golden tasks, pass/fail scoring, a tiny regression suite, one A/B, and a clear interview line for how goldens differ from unit tests and asset A/B.

Outcome

When you finish this pack, you can explain and run:

  1. What a golden task is (fixed scenario + expected behavior)
  2. Pass/fail scoring (not vibes)
  3. A tiny regression suite you re-run after a prompt/tool change
  4. One A/B (two configs, same goldens, compare scores)
  5. Interview one-liner: goldens ≠ unit tests ≠ asset time/token A/B
  6. Tag goldens with failure taxonomy IDs (spec drift, hallucinated API, loop inflation, test gaming, blast radius, silent arch)

Day map

Day Focus Do Time
1 Concepts Read Day 1 + self-check 30–40m
2 Design goldens Read Day 2; write 5 goldens on paper/md 30–45m
3 Run the lab Read Day 3 + run the offline lab locally 40–60m
4 Break & catch Change agent config; watch suite catch it 30–45m
5 A/B Two system prompts; compare scorecards 30–45m
6 Interview + close Day 6 lines; log proof in your skill notes 30m

Done when

  • 5+ goldens exist in the lab
  • A local suite run produces a scorecard
  • You deliberately made the agent worse and the suite dropped
  • You can say goldens ≠ unit tests ≠ asset A/B in one breath
  • Your skill notes record proof for the eval-harness axis

Anti-goals

  • Framework zoo (full platform tooling optional later)
  • Fake “IQ” or cognitive scores
  • Only reading social threads about evals
Lab note. The runnable Python lab stays offline in your study workspace. These pages are reading material and pointers only—no hosted backend.

Lessons

Days 1–6