Which cross-validation approach is specifically recommended for time series data where the relationship between features and target evolves over time?
Select an answer to reveal the explanation.
Short Explanation and Infographic
Here's the deal — c is correct because walk-forward CV respects temporal ordering — each fold trains on all data before the validation period and tests on subsequent data, preventing future information leakage. A (stratified k-fold) randomly shuffles data, destroying temporal structure.
Full explanation below image
Full Explanation
C is correct because walk-forward CV respects temporal ordering — each fold trains on all data before the validation period and tests on subsequent data, preventing future information leakage. A (stratified k-fold) randomly shuffles data, destroying temporal structure. B (LOOCV) also ignores temporal ordering when shuffled. D (repeated k-fold) introduces random shuffling incompatible with time-dependent data.