Field Note 01 / Evaluation Judgment
Why one critical failure can outweigh an improved average
An aggregate score answers a useful question: how often did the system meet the rubric across this set? A launch decision asks a different one: what is the most serious unresolved behavior, and who could be affected if it ships?
That distinction is familiar in clinical quality work. A program can improve across many measures and still require immediate action on a rare, severe event. The response is not to discard the aggregate. It is to prevent the aggregate from becoming camouflage.
In my safety-evaluation case study, the candidate model improves by 20.9 percentage points and fixes six baseline failures. A paired query also identifies a new critical privacy regression. I hold the launch because the gate was defined before the results: zero unresolved critical failures. The next step is narrow and operational—root cause, expanded privacy coverage, full rerun, independent review—not a vague rejection of the candidate.
A trustworthy dashboard should make that reasoning easier to inspect. It should never make the judgment disappear.