Towards Understanding the Influence of Training Samples on Explanations
André Artelt, Barbara Hammer
TL;DR
This work tackles the problem of tracing explanations back to training data by formalizing the notion of influential training samples that shape explanations in Explainable AI. It introduces a Data-SHAP–style gradient Monte Carlo algorithm to identify samples that strongly affect a given explanation, and applies it to two case studies involving counterfactual recourse: (i) the average cost of recourse and (ii) the cost-difference across protected groups. The methodology demonstrates that removing influential samples can reduce recourse costs and fairness disparities with limited degradation of predictive performance, and often performs better than standard Data-SHAP baselines in preserving accuracy. The findings have practical implications for data cleaning, fairness auditing, and trust in explanations, while also suggesting extensions to groups of samples and formal guarantees for the approximations used.
Abstract
Explainable AI (XAI) is widely used to analyze AI systems' decision-making, such as providing counterfactual explanations for recourse. When unexpected explanations occur, users may want to understand the training data properties shaping them. Under the umbrella of data valuation, first approaches have been proposed that estimate the influence of data samples on a given model. This process not only helps determine the data's value, but also offers insights into how individual, potentially noisy, or misleading examples affect a model, which is crucial for interpretable AI. In this work, we apply the concept of data valuation to the significant area of model evaluations, focusing on how individual training samples impact a model's internal reasoning rather than the predictive performance only. Hence, we introduce the novel problem of identifying training samples shaping a given explanation or related quantity, and investigate the particular case of the cost of computational recourse. We propose an algorithm to identify such influential samples and conduct extensive empirical evaluations in two case studies.
