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.