Timezone: »

Linear Relaxations for Finding Diverse Elements in Metric Spaces
Aditya Bhaskara · Mehrdad Ghadiri · Vahab Mirrokni · Ola Svensson

Mon Dec 05 09:00 AM -- 12:30 PM (PST) @ Area 5+6+7+8 #17

Choosing a diverse subset of a large collection of points in a metric space is a fundamental problem, with applications in feature selection, recommender systems, web search, data summarization, etc. Various notions of diversity have been proposed, tailored to different applications. The general algorithmic goal is to find a subset of points that maximize diversity, while obeying a cardinality (or more generally, matroid) constraint. The goal of this paper is to develop a novel linear programming (LP) framework that allows us to design approximation algorithms for such problems. We study an objective known as {\em sum-min} diversity, which is known to be effective in many applications, and give the first constant factor approximation algorithm. Our LP framework allows us to easily incorporate additional constraints, as well as secondary objectives. We also prove a hardness result for two natural diversity objectives, under the so-called {\em planted clique} assumption. Finally, we study the empirical performance of our algorithm on several standard datasets. We first study the approximation quality of the algorithm by comparing with the LP objective. Then, we compare the quality of the solutions produced by our method with other popular diversity maximization algorithms.

Author Information

Aditya Bhaskara (University of Utah)
Mehrdad Ghadiri (Sharif University of Technolog)
Vahab Mirrokni (Google)
Ola Svensson (EPFL)

More from the Same Authors