The fragmentation thesis is still considered one of the central questions in communication science. It postulates that the increasing diversification of media offerings (supply level) initiates a specialization of individual user behavior (usage level), which causes the traditional mass audience to disintegrate into a multitude of isolated, homogeneous sub-publics – with corresponding negative consequences for social integration, such as the disintegration of the public sphere and spreading polarization (effects level). In the age of digitization, buzzwords such as filter bubble or echo chamber were used in this context to conjure dangers of algorithmically induced, one-sided information environments that would intensify the fragmentation of the public. The popularity of the metaphors and the object od research is contrasted by a comparatively thin basis of empirical findings, which questions in particu-lar the existence of the much-cited filter bubbles and echo chambers.
The aim of the dissertation project is to elucidate the discrepancy between theory and empirical reality. The fragmentation thesis will first be subjected to a thorough theoretical review and update, on the basis of which hypotheses will be developed to investigate empirical developments on the three levels of the fragmentation process. At the core of the work will be a detailed analysis of the effects level of fragmentation, which in particular considers the role of pre-existing attitudes and other intervening variables in the reception of media content in the fragmentation process in a study design that can reveal causalities.
Daniel Stegmann M.A.