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Interpretable feature subset selection: A Shapley value based approach
Sandhya Tripathi, N. Hemachandra, Prashant Trivedi
January 12, 2020
arXiv.org
3 citations
Key Takeaways
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Shapley values can identify which features truly matter for predictions: The research shows that features with Shapley value scores above zero are those whose interactions are genuinely significant for making accurate predictions, providing a mathematically principled way to distinguish important features from noise.
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The method reveals a hidden gap between ideal and real-world classifiers: The approach identifies features that theoretical "perfect" classifiers wouldn't need, but that practical machine learning models trained on limited data actually rely on—this gap explains why real classifiers make more errors than theoretically possible.
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Feature importance scores become more reliable with multiple data samples: Rather than trusting a single feature importance ranking, the method provides confidence intervals by testing across multiple subsamples of data, making the results more robust and trustworthy for decision-making.
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Computational efficiency was addressed for practical use: While Shapley values are notoriously expensive to calculate, the authors implemented a Monte Carlo approximation that only computes necessary calculations "when needed," making the approach feasible for real-world applications rather than just theoretical exercises.
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Better performance than existing methods on real datasets: The scheme outperformed recursive feature elimination, a standard industry approach, suggesting that Shapley-based feature selection could improve model transparency and performance in practice.