Empirical analysis of structural properties, macroscopic and microscopic evolution of various Facebook activity networks

摘要

Recently, some works have been done in studying activity network as a more realistic representation of users' behavior in online social networks. However, there is a major deficiency of a suitable definition of activity network based on a comprehensive study of various activity networks separately and combined. The main purpose of our research is to understand the differences between users' behavior by various Facebook activities, so as to claim that these networks should not be blindly composed; neither should the result of analyzing each of them individually be generalized to others. For this purpose, degree distribution, small-world phenomenon, degree correlation, reciprocity, and homophily by different attributes of various activity networks are studied. Then, we study densification and shrinking diameter properties and some structural characteristics of activity networks over time. We also examine microscopic evolution of different activity networks. Ultimately, we conclude that there are some differences between users' behavior by various Facebook activities but all evolve almost similarly at macroscopic and microscopic levels. However, post network evolves considerably different from other activity networks. Accordingly, a comprehensive definition for activity network is suggested so that the results of analyzing the modeled activity network fit realistic data.