Effects of Group Categories on the Structure of Online Social Networks

Over the past few years there has been increasing research interests spent on online social networks. While some social networking sites such as Orkut, Facebook and Friendster are purely social, others such as YouTube, Flickr, and LiveJournal are highly content oriented while maintaining a social component too. The nature of the interaction between content and connections is fundamentally important not just from a social science perspective but also to answer how the relevant content and connections can be found more easily. YouTube more recently added the ability for users to form explicit groups, in which explicit category affiliation is noted too. YouTube is ripe for consideration of how content and contacts are related. We study YouTube groups in general not only in the context of categories but also study what motivates group membership in YouTube in the context of other observable group activities. We also investigate the role of users in groups, how groups evolve and the structure of these groups organized under a category change over time. Finally we find what form of linkage motivates new members to join these groups in YouTube