arxivcs.LG2026-07-04
Validation-Induced Shapley Shifts: How Validation Structure Distorts Data Valuation
Yinan Shen, Ziao Yang, Hongfu Liu
Shapley values are widely used to attribute value to training data based on their marginal contribution to performance on a validation set. Existing practice often assumes these values are stable once the training data and model are fixed. In this work, we uncover a systematic vu…