My general interests are in the field of (new) media research, in particular the phenomenon of fact-checking. Fact-checking is a new form of political monitoring, predominantly undertaken by civil society initiatives, which is challenging the traditional information and control function of professional media. Because the phenomenon developed only in the last decade, evidence about its diffusion and the different forms it takes in various media system settings is still scarce. The research project investigates why fact-checking, after having spread across many different world regions, takes rather distinctive forms in different media systems and societal contexts. Using a multi-level and multi-method research design which combines an in-depth multi-level comparison of individual national fact-checking initiatives with a comparative analysis of a data set containing information on all fact checking initiatives worldwide, the study aims to analyze how fact-checking has been adapted locally in different countries and might affect their national media systems.