What problem does it solve? Choosing the wrong metric or evaluating on leaky data produces models that look good in notebooks but fail in production. This Skill provides a rigorous evaluation framework that aligns metrics with business costs, quantifies uncertainty, and surfaces fairness issues before deployment. ## Core Features & Use Cases - Metric Selection & Computation: Maps task types (binary classification, regression, ranking, survival) to appropriate primary metrics like AUC-ROC, AUC-PR, F1, NDCG@K, and cost-sensitive custom metrics. - Statistical Rigor: Computes bootstrap confidence intervals, calibration curves with Expected Calibration Error, and threshold analysis across decision boundaries. - Fairness & Go/No-Go Decisions: Evaluates performance across demographic subgroups, detects AUC/FNR disparities, and produces evidence-based go/no-go recommendations against requirements. - Use Case: Before promoting a fraud detection model to production, run the evaluator on a held-out test set with cost_fp=1 and cost_fn=10, verify recall meets the 0.65 requirement with confidence intervals, and confirm no fairness disparity across age groups. ## Quick Start Evaluate my trained classifier on the test set with bootstrap confidence intervals, calibration analysis, and a fairness check across customer segments, then give me a go/no-go recommendation.