Fair Clustering for Data Summarization: Improved Approximation Algorithms and Complexity Insights
2025 (English) In: WWW 2025 - Proceedings of the ACM Web Conference, Association for Computing Machinery (ACM) , 2025, p. 4458-4469Conference paper, Published paper (Refereed)
Abstract [en]
Data summarization tasks are often modeled as k-clustering problems, where the goal is to choose k data points, called cluster centers, that best represent the dataset by minimizing a clustering objective. A popular objective is to minimize the maximum distance between any data point and its nearest center, which is formalized as the k-center problem. While in some applications all data points can be chosen as centers, in the general setting, centers must be chosen from a predefined subset of points, referred as facilities or suppliers; this is known as the k-supplier problem. In this work, we focus on fair data summarization modeled as the fair k-supplier problem, where data consists of several groups, and a minimum number of centers must be selected from each group while minimizing the k-supplier objective. The groups can be disjoint or overlapping, leading to two distinct problem variants each with different computational complexity. We present 3-approximation algorithms for both variants, improving the previously known factor of 5. For disjoint groups, our algorithm runs in polynomial time, while for overlapping groups, we present a fixed-parameter tractable algorithm, where the exponential runtime depends only on the number of groups and centers. We show that these approximation factors match the theoretical lower bounds, assuming standard complexity theory conjectures. Finally, using an open-source implementation, we demonstrate the scalability of our algorithms on large synthetic datasets and assess the price of fairness on real-world data, comparing solution quality with and without fairness constraints.
Place, publisher, year, edition, pages Association for Computing Machinery (ACM) , 2025. p. 4458-4469
Keywords [en]
Algorithmic bias, Algorithmic fairness, Fair clustering, Fair k-center, Fair k-supplier, Responsible computing
National Category
Computer Sciences Computer graphics and computer vision
Identifiers URN: urn:nbn:se:kth:diva-363997 DOI: 10.1145/3696410.3714857 ISI: 001505285200370 Scopus ID: 2-s2.0-105005145530 OAI: oai:DiVA.org:kth-363997 DiVA, id: diva2:1962833
Conference 34th ACM Web Conference, WWW 2025, Sydney, Australia, April 28 - May 2, 2025
Note Part of ISBN 9798400712746
QC 20250603
2025-06-022025-06-022025-12-08 Bibliographically approved