The many facets of community detection in complex networks

TL;DR

This paper reviews various motivations and methods for community detection in complex networks, emphasizing the importance of selecting algorithms based on specific goals and highlighting future research directions.

Contribution

It offers a problem-driven classification of community detection methods, clarifying different motivations and guiding their application in network science.

Findings

Highlights diverse motivations behind community detection

Classifies algorithms based on their underlying goals

Identifies open research directions in the field

Abstract

Community detection, the decomposition of a graph into essential building blocks, has been a core research topic in network science over the past years. Since a precise notion of what constitutes a community has remained evasive, community detection algorithms have often been compared on benchmark graphs with a particular form of assortative community structure and classified based on the mathematical techniques they employ. However, this comparison can be misleading because apparent similarities in their mathematical machinery can disguise different goals and reasons for why we want to employ community detection in the first place. Here we provide a focused review of these different motivations that underpin community detection. This problem-driven classification is useful in applied network science, where it is important to select an appropriate algorithm for the given purpose. Moreover, highlighting the different facets of community detection also delineates the many lines of research and points out open directions and avenues for future research.