2.9.1. Cross Validation# This chapter outlines the importance of Cross Validation, the different methods that exist and how to leverage them 2.9.1.1. K-Fold CV# 2.9.1.2. Stratified K-Fold CV# 2.9.1.3. LOOO CV# 2.9.1.4. Hold out CV# 2.9.1.5. Time Series Rolling CV#