Mesoscopic analysis of online social networks - The role of negative ties

TL;DR

This study investigates how positive and negative ties influence community structures in signed social networks, revealing that negative ties mainly occur between communities and that mediator triads are significant but often overlooked.

Contribution

It demonstrates that negative ties are less influential in community detection and highlights the importance of considering mediator triads for accurate mesoscopic analysis.

Findings

Negative ties mostly occur between communities.

Most unbalanced communities are maximally balanced internally.

Mediator triads are underrepresented but significant.

Abstract

A class of networks are those with both positive and negative links. In this manuscript, we studied the interplay between positive and negative ties on mesoscopic level of these networks, i.e., their community structure. A community is considered as a tightly interconnected group of actors; therefore, it does not borrow any assumption from balance theory and merely uses the well-known assumption in the community detection literature. We found that if one detects the communities based on only positive relations (by ignoring the negative ones), the majority of negative relations are already placed between the communities. In other words, negative ties do not have a major role in detecting communities of studied signed networks. Moreover, regarding the internal negative ties, we proved that most unbalanced communities are maximally balanced, and hence they cannot be partitioned into k nonempty sub-clusters with higher balancedness (k >= 2). Furthermore, we showed that although the mediator triad ++- (hostile-mediator-hostile) is underrepresented, it constitutes a considerable portion of triadic relations among communities. Hence, mediator triads should not be ignored by community detection and clustering algorithms. As a result, if one uses a clustering algorithm that operates merely based on social balance, mesoscopic structure of signed networks significantly remains hidden.