Intermedia agenda setting in an era of fragmentation: Applications of network science in the study of mass communication

This work proposes a relational approach to the study of news agendas and media fragmentation in a digital age. It examines the origins, development, and current status of mass communication theories dealing with news selection and impact. Recent conceptual and methodological challenges facing research in a changing information environment are discussed. A broad analytical strategy exploring the media system as a dynamic multilevel, multidimensional network is outlined. Implementing this approach, the study sets out to evaluate fragmentation levels and factors predicting agenda convergence in a longitudinal network of news outlets. The analysis is based on secondary data collected by the Pew Center's Project for Excellence in Journalism (2008) and the 2008 National Annenberg Election Survey. The study sample contains U.S. news outlets from five industry sectors: newspapers, online sources, radio, cable and network TV stations.;The results uncover a decrease in fragmentation over time, with a minimum reached during the U.S. presidential elections in November 2008. The dynamics of agenda convergence are found to be shaped by the story selections of popular outlets and driven by similarities in format, audience demographics, and political ideology. Audience size does not significantly influence the correspondence in news source agendas over time. The analysis also shows that co-ownership relations lead to lower agenda convergence for the outlets in the sample.