Growth in online social networks: sheer volume vs social interaction

Abstract

The theme of today’s Internet services is social networking. Users who use those services are getting used to interact each other through these features: making friend relationships, sharing their interest, and writing comments. Recent studies about social networks focus on the explicit friend relations. Friend relations, however, are not enough to represent real activity on online social networks because friend networks are static. In this paper, we suggest to move the focus on analysis of online social networks from friend network to activity network for deeply understanding online social networks. Our activity network topology is constructed using complete guestbook logs of Cyworld. Two factors: the number of one’s friend and one’s reciprocity with other users affect users’ activity. In this process, we find that there exists a limitation in one’s ability of managing friends online. Since we want to find the hub users in online social network, we define the steady core which consists of both active and steady users. We also study topological characteristics of steady core. Finally, we compare friendship network with activity network in the point of view of power users and overlapped nodes and edges.