Graph clustering

In this survey we overview the definitions and methods for graph clustering, that is, finding sets of "related" vertices in graphs. We review the many definitions for what is a cluster in a graph and measures of cluster quality. Then we present global algorithms for producing a clustering for the entire vertex set of an input graph, after which we discuss the task of identifying a cluster for a specific seed vertex by local computation. Some ideas on the application areas of graph clustering algorithms are given. We also address the problematics of evaluating clusterings and benchmarking cluster algorithms. (C) 2007 Elsevier Ltd. All rights reserved.