3. Model-agnostic methods# 3.1. Conditional Feature Importance 3.1.1. Theoretical index 3.1.2. Estimation procedure 3.1.3. Inference 3.1.4. Regression example 3.1.5. Classification example 3.1.6. References 3.2. Permutation Feature Importance 3.2.1. Theoretical index 3.2.2. Estimation procedure 3.2.3. Inference 3.2.4. Regression example 3.2.5. Classification example 3.2.6. References 3.3. Leave-One-Covariate-Out