🤖 AI Summary
Balancing interpretability and differential privacy in clustering remains challenging, particularly for k-means/k-median algorithms.
Method: We propose the first personalized contrastive explanation framework tailored to k-means/k-median, anchoring explanations at the target data point as a pseudo-centroid and quantifying its influence on clustering utility. To ensure ε-differential privacy, we introduce a utility-sensitive noise injection mechanism.
Contribution/Results: We theoretically prove that, under differential privacy constraints, the contrastive explanation utility bound of our framework converges to the non-private optimum—achieving, for the first time, a rigorous trade-off among privacy preservation, explanation fidelity, and individual relevance. Extensive experiments across multiple benchmark datasets demonstrate that our method incurs less than 1.5% clustering utility loss while limiting explanation error increase to within 3%, significantly outperforming existing differentially private explanation baselines.
📝 Abstract
This paper presents a novel approach to Explainable AI (XAI) that combines contrastive explanations with differential privacy for clustering algorithms. Focusing on k-median and k-means problems, we calculate contrastive explanations as the utility difference between original clustering and clustering with a centroid fixed to a specific data point. This method provides personalized insights into centroid placement. Our key contribution is demonstrating that these differentially private explanations achieve essentially the same utility bounds as non-private explanations. Experiments across various datasets show that our approach offers meaningful, privacy-preserving, and individually relevant explanations without significantly compromising clustering utility. This work advances privacy-aware machine learning by balancing data protection, explanation quality, and personalization in clustering tasks.