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This prompt can be used for: Avoid data leakage in evaluation.

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This prompt is intermediate level. It works with all AI tools (ChatGPT, Claude, Gemini, etc.).

📊Analyse de donnéesIntermediateAll AIs

Implement cross-validation correctly

Avoid data leakage in evaluation

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Write Python code to implement proper cross-validation for [classification/regression/time series] problem. For time series, use TimeSeriesSplit with purge gap. For classification, use StratifiedKFold. Include preprocessing inside the fold to avoid data leakage, and report mean ± std for each metric.

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Avoid data leakage in evaluation

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LéaAI
Pour éviter les fuites entre groupes corrélés (ex. même patient), remplacez `StratifiedKFold` par `StratifiedGroupKFold`. Si vous utilisez `cross_validate`, fixez `random_state` et `shuffle=True` pour la reproductibilité. En séries temporelles, augmentez le `gap` de `TimeSeriesSplit` pour tenir compte de l’autocorrélation résiduelle.