evaluating-binary-classifiers

Evaluate binary classifiers with ROC-AUC, PR-AUC, calibration, and bootstrap confidence intervals.

2|Updated May 23, 2026
One-click install
npx skills add https://github.com/rocklambros/rcs --skill evaluating-binary-classifiers
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: evaluating-binary-classifiers
Source: https://github.com/rocklambros/rcs/tree/main/skills/ml-datasci/evaluating-binary-classifiers
Command: npx skills add https://github.com/rocklambros/rcs --skill evaluating-binary-classifiers

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

This Skill turns a trained binary classifier into a defensible evaluation report so you can judge real performance instead of relying on a single misleading number.

Core Features & Use Cases

  • Balanced and imbalanced evaluation: Checks class balance first and reframes the report around PR-AUC when the positive class is rare.
  • Threshold-aware analysis: Compares multiple thresholds, avoids defaulting to 0.5, and selects an operating point using cost-aware or precision-floor rules.
  • Calibration and uncertainty: Adds reliability analysis, Brier score, confusion matrices, and bootstrap confidence intervals for key metrics.
  • Use case: Review a spam, fraud, or medical screening model from held-out predictions and produce a complete, production-style evaluation.

Quick Start

Ask for a full binary-classifier evaluation from y_true and y_pred_proba, including class balance, ROC and PR analysis, calibration, threshold selection, and bootstrap confidence intervals.

Frequently Asked Questions about evaluating-binary-classifiers

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I evaluate a binary classifier on imbalanced data?

Evaluating a binary classifier on imbalanced data requires reframing the report around PR-AUC instead of standard accuracy. This Skill checks class balance first and applies precision-recall metrics to handle rare positive classes effectively.

How can I find the optimal decision threshold for a binary classification model?

Finding the optimal decision threshold involves sweeping multiple values instead of defaulting to 0.5. This Skill compares thresholds and selects an operating point using cost-aware or precision-floor rules to match your production requirements.

What metrics are needed for a complete binary classification scoring report?

A complete binary classification scoring report needs ROC-AUC, PR-AUC, calibration, confusion matrices, and bootstrap confidence intervals. This Skill generates all these metrics from your held-out test sets to provide defensible performance analysis.

Does this binary classifier evaluation support cost-aware decision handling?

Yes, this binary classifier evaluation supports cost-aware decision handling. It selects operating points using cost-aware rules during threshold sweeps, making it suitable for fraud and medical screening workflows where false positives and negatives carry different weights.

How do I calculate bootstrap confidence intervals for ROC-AUC and PR-AUC?

Calculating bootstrap confidence intervals for ROC-AUC and PR-AUC involves resampling your test predictions. This Skill computes bootstrap confidence intervals for key metrics automatically, adding reliability analysis and Brier scores to your evaluation report.

Why does my binary classifier accuracy score not reflect real performance?

Binary classifier accuracy often fails to reflect real performance because it masks poor minority class detection in imbalanced datasets. This Skill solves the problem by evaluating calibration, PR-AUC, and threshold-aware metrics to judge actual model behavior.