experiment · growing

Evals before prompts

Twenty cases and a diff beat any amount of prompt intuition.

Prompt tuning without evals is just vibes with extra steps. The eval does not need to be sophisticated; it needs to exist before the prompt changes.

the smallest useful harness
20 casesreal inputs
Runfixed seed
Graderubric or assert
Diffvs last run

Starting set

KindCountWhat it catches
Golden10regressions on the happy path
Adversarial5prompt injection, refusal bait
Boring5empty input, huge input, wrong language

Grading with a model

Use one when the answer is genuinely open-ended, and then:

  • Grade one dimension at a time. A single "is this good" score is noise.
  • Give the judge the rubric and a reference answer.
  • Track judge/human agreement on a sample. A judge you have never audited is a random number generator with good manners.
#evals #testing

See this note on the whiteboard →