03. Cross-Validation
AI For Trading C6 L2 A03 Cross-Validation V2
Enhancing Model Generalization with Data Splitting
Effective machine learning models must generalize to unseen data. Achieving this involves strategic use of training data without compromising assessment integrity.
Data Importance: Models improve with more training data. However, evaluating on the same data skews results.
Holdout Method: Divide data into training (70-90%) and test (10-30%) sets.
- Ensure test data is unseen to fairly evaluate model quality.
Validation Set: Further split training data for model tuning.
- Train multiple models, selecting the best via calculated validation scores.
Cross-Validation (CV): For a robust performance estimate:
- Utilize multiple training-validation splits, averaging results.
- K -old CV divides data into K equal subsets.
- Each fold acts as a validation set once while others train the model.
Stratified K fold CV: Maintains target class distribution in each split, crucial for imbalanced datasets.
Temporal Data Warning: Avoid cross-validation for time-sequential features; different techniques apply.
This foundational understanding aids in developing data-efficient models with reliable prediction capabilities.