Online Social Networks: Essays on Membership, Privacy, and Structure

The structure of social networks is crucial for obtaining social support, for meaningful connections to unknown social groups, and to overcome prejudice. Yet, we know little about the structure of social networks beyond those contacts that stand closest to us. This lack of knowledge results from a survey-research tradition in which solely strong social ties are mapped. This dissertation overcomes this issue by embracing a new feature of contemporary social life: the fact that individuals overwhelmingly maintain their social relationships online. The “digital footprints” of interactions left online enable scholars to test old and new theories on the structure of social networks in innovative ways. In this spirit, the goal of this dissertation is to understand the structure of online social networks for new insights into the structure of social networks in general. What are the theoretical and empirical promises and pitfalls of such a study? Bas Hofstra answers these questions through five empirical chapters in which he links offline survey data on Dutch adolescents with online network data from Facebook.