Structural correlation between communities and core-periphery structures in social networks: Evidence from Twitter data

Social media, such as Twitter and Facebook, have become important venues for business and individuals. Social interactions between actors result in the formation of meso-scale subgroup structures, such as communities. Community detection is a classic task of social network analysis. Identification of another meso-scale structure, named core-periphery, arises recently. Much existing research discriminated communities from core-periphery structures, and performed the two tasks individually by completely different methodologies. The two meso-scale structures can both attribute to unequal influence and asymmetric interactions of actors in social networks. This research tries to unify communities and core-periphery structures by regarding the two subgroup structures as the same thing, by which community structure characterizes the boundary of a subgroup and core-periphery structure characterizes its internal structure. Experiments are conducted on one-month twitter data, and results can provide empirical evidences that social communities always have core-periphery structures. (C) 2017 Elsevier Ltd. All rights reserved.