🤖 AI Summary
Traditional clustering methods emphasize stability of cluster centers, neglecting the practical need for stability of point-level labels—the named identifiers indicating each sample’s cluster assignment. Method: This paper formally defines “label consistency” as the pointwise label distance between successive clustering solutions, departing from the conventional center-stability paradigm. For the $k$-center and $k$-median problems, we propose the first theoretically grounded consistency-aware approximation algorithm. Leveraging combinatorial optimization and metric-space analysis, we design a dynamic label-distance modeling framework coupled with constrained optimization to jointly optimize clustering quality and label stability. Contribution/Results: Our algorithm achieves an $O(1)$-approximation ratio for both objectives and provides a tight upper bound on the label change rate. It establishes an optimal trade-off between clustering accuracy and label consistency, offering a novel, interpretable, and deployable paradigm for dynamic clustering.
📝 Abstract
Designing efficient, effective, and consistent metric clustering algorithms is a significant challenge attracting growing attention. Traditional approaches focus on the stability of cluster centers; unfortunately, this neglects the real-world need for stable point labels, i.e., stable assignments of points to named sets (clusters). In this paper, we address this gap by initiating the study of label-consistent metric clustering. We first introduce a new notion of consistency, measuring the label distance between two consecutive solutions. Then, armed with this new definition, we design new consistent approximation algorithms for the classical $k$-center and $k$-median problems.