The importance of social media for political participation and opinion-forming is constantly increasing. However, the consequences of political activities online for more demanding political acts (such as voting behaviour) have so far only been empirically researched in rudimentary form. This is mainly due to the fact that the connection between online behaviour and political attitudes and traditional participation at the individual level is methodologically difficult to establish. The symposium will address this problem. Experiences will be exchanged and proposals developed for linking survey and social media data.