Data valuation has become an increasingly significant discipline in data science due to the economic value of data. In the context of machine learning (ML), data valuation methods aim to equitably measure the contribution of each data point to the utility of an ML model. One prevalent method is Shapley value, which helps identify data points that are beneficial or detrimental to an ML model. However, traditional Shapley-based data valuation methods may not effectively distinguish between beneficial and detrimental training data points for probabilistic classifiers. In this paper, we propose Probabilistic Shapley (P-Shapley) value by constructing a probability-wise utility function that leverages the predicted class probabilities of probabilistic classifiers rather than binarized prediction results in the traditional Shapley value. We also offer several activation functions for confidence calibration to effectively quantify the marginal contribution of each data point to the probabilistic classifiers. Extensive experiments on four real-world datasets demonstrate the effectiveness of our proposed P-Shapley value in evaluating the importance of data for building a high-usability and trustworthy ML model.

本文提出了一种概率Shapley值（P-Shapley），通过构建一个基于概率分类器的类概率效用函数来量化每个数据点对概率分类器的边际贡献，并提供几种置信度校准的激活函数，从而实现评估数据重要性以构建高可用性和可信赖性ML模型的目的。

概率分类器上的 Shapley 值