3. Model-agnostic methods# 3.1. Total Sobol Index 3.2. Leave-One-Covariate-Out 3.3. Conditional Feature Importance 3.3.1. Theoretical index 3.3.2. Estimation procedure 3.3.3. Inference 3.3.4. Regression example 3.3.5. Classification example 3.3.6. References 3.4. Permutation Feature Importance