Identifying Leaders and Followers in Online Social Networks

Identifying leaders and followers in online social networks is important for various applications in many domains such as advertisement, community health campaigns, administrative science, and even politics. In this paper, we study the problem of identifying leaders and followers in online social networks using user interaction information. We propose a new model, called the Longitudinal User Centered Influence (LUCI) model, that takes as input user interaction information and clusters users into four categories: introvert leaders, extrovert leaders, followers, and neutrals. To validate our model, we first apply it to a data set collected from an online social network called Everything2. Our experimental results show that our LUCI model achieves an average classification accuracy of up to 90.3% in classifying users as leaders and followers, where the ground truth is based on the labeled roles of users. Second, we apply our LUCI model on a data set collected from Facebook consisting of interactions among more than 3 million users over the duration of one year. However, we do not have ground truth data for Facebook users. Therefore, we analyze several important topological properties of the friendship graph for different user categories. Our experimental results show that different user categories exhibit different topological characteristics in the friendship graph and these observed characteristics are in accordance with the expected ones based on the general definition of the four roles.