Statistical technique for robustly evaluating and comparing predictive models by repeatedly splitting data into training and test sets.
Cross-validation is a statistical technique for evaluating predictive models by repeatedly partitioning datasets into training and test folds; it reduces overfitting and provides more reliable performance estimates. Different strategies (k‑fold, stratified, time‑series split) address data characteristics and bias. Applying it requires choosing a validation strategy that matches data structure and business questions.
Aggregated performance metric across all folds (e.g. mean accuracy).
Measure of model stability and sensitivity to data variations.
Total runtime of validation runs as indicator of practicality.
Participants use k‑fold cross‑validation to robustly estimate public/private leaderboard performance.
Practical example using cross_val_score and GridSearchCV for model selection.
Rolling-window validation to safeguard production forecasts across seasonal cycles.
Inspect data and target; choose appropriate fold strategy
Encapsulate preprocessing inside folds (pipeline)
Run cross-validation and aggregate metrics
Interpret results, check variance and make decision