SHAP Model Explainability

Overview

SHAP (SHapley Additive exPlanations) is a unified framework for explaining machine learning model predictions using Shapley values from cooperative game theory. It quantifies each feature's contribution to individual predictions and provides both local (per-instance) and global (dataset-level) explanations with theoretical guarantees of consistency and additivity.

When to Use

• Explaining which features drive a model's predictions (global importance)
• Understanding why a model made a specific prediction (local explanation)
• Debugging model behavior and identifying data leakage
• Analyzing model fairness across demographic groups
• Comparing feature importance across multiple models
• Generating interpretable model explanations for stakeholders
• For tree-based model interpretation, prefer SHAP over permutation importance or Gini importance (more accurate, instance-level)
• For deep learning interpretation on images, consider GradCAM; use SHAP for tabular/structured data

Prerequisites