Mastery: connect the pieces

1. Idea — An evaluation is your measuring instrument; a benchmark is a shared test protocol. Neither is the whole truth about production quality.…
2. Mechanism — Define tasks and labels/rubrics, freeze versions, run the system, score with deterministic checks and/or human raters, compare against baselines, and watch for …
3. Controls — case set size, slice definitions, scorer type, contamination checks, seed/decoding freeze, human rubric
4. Tradeoff — Bigger suites cost more and stabilize estimates. Model judges scale and inherit biases. Public benchmarks aid comparison and risk train-set overlap.…
5. Failures — Contamination; Metric myopia
6. Metrics — pass rate with CI, slice gaps, scorer agreement, contamination indicators, cost per accepted task
7. Ship rule — Gate releases on private 120-task suite: severe fails=0, pass ≥ baseline+3 on target slice, public benchmark as smoke only.

Neighboring layers (retrieval, serving, policy, human review) still own what evals and benchmarks cannot on the coding copilot. Do not ask this chapter’s dial to replace permissions or source truth.

Mastery is transfer: take evals and benchmarks into a second scenario that is not the coding copilot and rebuild the checklist without copying sentences. If you can only recite this chapter’s examples for evals and benchmarks, you have memorized a story, not a model.

Also pin one numeric memory from this evals and benchmarks chapter: 80/100 pass on unit-test tasks with 95% CI roughly ±4 pts—do not call a +2 pt vendor demo a revolution. That number is not decoration; it is a template for how claims about evals and benchmarks on the coding copilot should look in design docs. Scoped specifically to evals and benchmarks / coding copilot / mastery-connect.

People confuse evals and benchmarks with neighboring buzzwords when debugging the coding copilot. Before changing prompts, ask whether the broken stage was evidence gathering, the evals and benchmarks judgment itself, validation, or the product action. Fixing the wrong stage creates folklore (“we tried evals and benchmarks and it failed”) that blocks the next team on the coding copilot. Scoped specifically to evals and benchmarks / coding copilot / mastery-connect.

Write a five-line artifact for this page: goal, inputs, check, owner, stop rule. Invent one fluent failure that the check would catch. Keep details specific to eval and benchmarks rather than generic AI advice.