Ensemble-based Overlapping Community Detection using Disjoint Community Structures

TL;DR

EnCoD is an ensemble method that infers overlapping communities by combining disjoint community detection results, outperforming existing algorithms on synthetic and real-world networks.

Contribution

It introduces a novel ensemble approach, EnCoD, that derives overlapping communities from multiple disjoint community algorithms without developing separate methods.

Findings

EnCoD outperforms nine state-of-the-art algorithms on synthetic and real-world networks.

It is applicable to networks with explicit semantic vertex features.

EnCoD is the second ensemble-based overlapping community detection method.

Abstract

While there has been a plethora of approaches for detecting disjoint communities from real-world complex networks, some methods for detecting overlapping community structures have also been recently proposed. In this work, we argue that, instead of developing separate approaches for detecting overlapping communities, a promising alternative is to infer the overlapping communities from multiple disjoint community structures. We propose an ensemble-based approach, called EnCoD, that leverages the solutions produced by various disjoint community detection algorithms to discover the overlapping community structure. Specifically, EnCoD generates a feature vector for each vertex from the results of the base algorithms and learns which features lead to detect densely connected overlapping regions in an unsupervised way. It keeps on iterating until the likelihood of each vertex belonging to its own community maximizes. Experiments on both synthetic and several real-world networks (with known ground-truth community structures) reveal that EnCoD significantly outperforms nine state-of-the-art overlapping community detection algorithms. Finally, we show that EnCoD is generic enough to be applied to networks where the vertices are associated with explicit semantic features. To the best of our knowledge, EnCoD is the second ensemble-based overlapping community detection approach after MEDOC [1].