Structure and dynamics of online social networks

Several online social networks have emerged in the past twenty years, each with a different purpose. Some networks are designed for the user to connect to real-life friends (Facebook, Google+, Qzone, Myspace, VKontakte); others serve as a distribution channel for news or blogs (Twitter, Livejournal) without real-life contact; or they are game-related (Habbo, Friendster); or, finally, their scope is to create and maintain professional relationships (LinkedIn).

Social online networks have changed the way how individuals and groups distribute knowledge and information. Some questions logically arise: how does information propagate throughout these networks? Moreover, what are the differences in information flow between several networks? How do these networks emerge and what are the conditions for being robust against failures or collapse of a network?

Such questions pose a number of challenges, since most online social networks are temporal, i.e. their composition continuously changes. Furthermore, the most popular networks are enormous (hundred of millions of users & links), thus making analytic measurements and calculations impossible with the typical computational power available nowadays. Moreover, most of these data are not openly available, as this would infringe privacy of participating users.

Our goal is to address these challenges and use time-averaged or snapshot techniques, numerical approximations or sampling to investigate the structure and dynamics of these networks. By means of our exhaustive empirical analyses, we are able to determine the causes for the rise and the decline of several online social networks.

Selected Publications

Ideological and Temporal Components of Network Polarization in Online Political Participatory Media

Garcia, David; Abisheva, Adiya; Schweighofer, Simon; Serdult, Uwe; Schweitzer, Frank

Policy and Internet, pages: 46-79, volume: 7, number: 1


Who Watches ( and Shares ) What on YouTube ? And When ? Using Twitter to Understand YouTube Viewership

Abisheva, Adiya; Garimella, Venkata Rama Kiran; Garcia, David; Weber, Ingmar

In Proceedings of the 7th ACM international conference on Web search and data mining, pages: 593-602


Gender Asymmetries in Reality and Fiction : The Bechdel Test of Social Media

Garcia, David; Weber, Ingmar; Garimella, Rama Venkata Kiran

Proceedings of the International AAAI Conference on Weblogs and Social Media


Online Privacy as a Collective Phenomenon

Sarigol, Emre; Garcia, David; Schweitzer, Frank

In Proceedings of the 2nd Conference on Online Social Networks 2014


Resilience in Enterprise Social Networks

Burger, Valentin; Hofeld, Tobias; Garcia, David; Seufert, Michael; Scholtes, Ingo; Hock, David

In Proceedings of Informatik 2013, 43. Jahrestagung der Gesellschaft für Informatik e.V. (GI), Informatik angepasst an Mensch, Organisation und Umwelt, 16.-20. September 2013, Koblenz


Social resilience in online communities: The autopsy of Friendster

Garcia, David; Mavrodiev, Pavlin; Schweitzer, Frank

Proceedings of the 1st ACM Conference in Online Social Networks (COSN'13)


Emotional persistence in online chatting communities

Garas, Antonios; Garcia, David; Skowron, Marcin; Schweitzer, Frank

Scientific Reports, pages: 402, volume: 2


Personalised and Dynamic Trust in Social Networks

Walter, Frank Edward; Battiston, Stefano; Schweitzer, Frank

Proceedings of the third ACM conference on Recommender systems pages: 197-204