Fast-DataShapley: Neural Modeling for Training Data Valuation
Haifeng Sun, Yu Xiong, Runze Wu, Xinyu Cai, Changjie Fan, Lan Zhang, Xiang-Yang Li
TL;DR
This paper tackles the problem of valuing training data for single-test-sample predictions using Shapley values, which are theoretically sound but computationally prohibitive as data providers grow. It introduces Fast-DataShapley, a one-pass, learned explainer that predicts training-data Shapley values for any new test sample without retraining the target model, leveraging a CWLS-style formulation with a prediction-specific value function. To reduce training overhead, it proposes three methods AFDS, GFDS, and GFDSPlus, offering theoretical guarantees and trade-offs between accuracy and efficiency; AFDS uses early-epoch information, GFDS groups data to reduce coalition size, and GFDSPlus adds symmetry-based grouping. Empirical results on MNIST and CIFAR-10 show substantial improvements in value estimation and dramatic reductions in training time, indicating strong practical potential for fair data compensation and copyright attribution in AI systems, with room for extension to generative tasks and privacy-preserving considerations.
Abstract
The value and copyright of training data are crucial in the artificial intelligence industry. Service platforms should protect data providers' legitimate rights and fairly reward them for their contributions. Shapley value, a potent tool for evaluating contributions, outperforms other methods in theory, but its computational overhead escalates exponentially with the number of data providers. Recent works based on Shapley values attempt to mitigate computation complexity by approximation algorithms. However, they need to retrain for each test sample, leading to intolerable costs. We propose Fast-DataShapley, a one-pass training method that leverages the weighted least squares characterization of the Shapley value to train a reusable explainer model with real-time reasoning speed. Given new test samples, no retraining is required to calculate the Shapley values of the training data. Additionally, we propose three methods with theoretical guarantees to reduce training overhead from two aspects: the approximate calculation of the utility function and the group calculation of the training data. We analyze time complexity to show the efficiency of our methods. The experimental evaluations on various image datasets demonstrate superior performance and efficiency compared to baselines. Specifically, the performance is improved to more than 2 times, and the explainer's training speed can be increased by two orders of magnitude.
