My doctoral dissertation (defended a few months back) studies a dynamic network of news outlets and the topics they cover over time. It implements a measure of media fragmentation and uses actor-based modeling to evaluate the impact of economic, political, organizational, and structural forces on certain properties of the media agenda. The key factors I look into include popularity, ownership, format, audience demographics, and political ideology. The research sample consists of large mainstream sources – print, TV, radio, and online news.
I ran analyses on, among other things, 5 years of media monitoring data collected by the Pew Project for Excellence in Journalism. The video below shows the network dynamics for major topics covered in 2008. That includes coverage of the presidential primaries and elections, as well as other events during the year. The visualization was created using R and Gephi.
As shown in the static image below, the circle of blue nodes represents key topics in the news (each of those is labeled in the dynamic viz). The smaller nodes in the center are media outlets. As news sources focus on different issues over time, the size of the topic nodes grows and shrinks. News outlets also move closer to the topics they cover most frequently.