git:20260502.9bb8dc1 to git:20260605.687eb4a

38 added, 8 removed. Audit A to A.

---
name: model-evaluation-reporting
- description: "Standardize the reporting of model metrics to ensure statistical rigor and business relevance."
+ description: Use when writing or reviewing a model evaluation report -- accuracy is being quoted alone, or stakeholders need failure modes, segment performance, and business trade-offs made explicit.
---
- # Model Evaluation Reporting
+ ## Purpose
- Raw accuracy metrics are not enough. Evaluation must reflect the actual business impact and failure modes of the model.
+ Raw accuracy metrics are not enough. Evaluation must reflect the actual business impact and failure modes of the model; this standard turns metrics into a report a stakeholder can act on.
- ## Reporting Standards
+ ## When to Use
- 1. **Beyond Accuracy**: Demand the Confusion Matrix. Demand Precision, Recall, and F1. Explain the cost of a False Positive vs. a False Negative in the business context.
- 2. **Slice Analysis**: Report performance on key segments. A model might be 95% accurate overall, but only 40% accurate on new users.
- 3. **Calibration**: If the model outputs probabilities, verify if they are calibrated. A prediction of 0.8 should mean it happens 80% of the time.
- 4. **Action**: Format the output as a Markdown report that a non-technical stakeholder can read, highlighting trade-offs and worst-case scenarios.
+ - Producing an evaluation report for a trained model
+ - Reviewing a report that quotes a single headline metric
+ - A go/no-go decision depends on understanding error costs
+
+ ## Inputs
+
+ - Model predictions on a held-out set
+ - Business context: cost of errors, key user/customer segments
+
+ ## Workflow
+
+ 1. **Beyond accuracy**: include the confusion matrix; report Precision, Recall, and F1; explain the cost of a False Positive vs a False Negative in the business context.
+ 2. **Slice analysis**: report performance on key segments. A model can be 95% accurate overall but only 40% accurate on new users.
+ 3. **Calibration**: if the model outputs probabilities, verify they are calibrated — a prediction of 0.8 should come true about 80% of the time.
+ 4. **Format as a Markdown report** that a non-technical stakeholder can read, highlighting trade-offs and worst-case scenarios.
+
+ ## Output
+
+ - A Markdown evaluation report: headline metrics, confusion matrix, per-segment table, calibration assessment, and explicit trade-offs/worst cases
+
+ ## Verification
+
+ - [ ] Confusion matrix plus Precision/Recall/F1 present (not accuracy alone)
+ - [ ] False Positive vs False Negative costs stated in business terms
+ - [ ] Key segments sliced and reported
+ - [ ] Calibration assessed whenever probabilities are output
+ - [ ] Report readable by a non-technical stakeholder
+
+ ## Failure Modes
+
+ - **Headline-metric reporting** — one aggregate number hides segment failures; always include slices.
+ - **Cost-free framing** — treating FP and FN as equivalent when their business impact differs by orders of magnitude.
+ - **Uncalibrated probabilities read as confidence** — stakeholders will read 0.8 as "80% sure"; verify calibration before they do.
+