Ernste, Thomas John2014-02-282014-02-282014-01https://hdl.handle.net/11299/162639University of Minnesota Ph.D. dissertation. January 2014. Major: Mass Communication. Advisor: Dan Sullivan. 1 computer file (PDF); ix, 247 pages.This dissertation describes the development of a networked gatekeeping theory for the study of an increasingly internet-mediated news diffusion process. Prior gatekeeping research provides a rich theoretical and methodological framework for investigating and illuminating the process through which certain events and issues on an international, national, and local level become the mediated messages that reach the public. Towards a framework for reconceptualizing gatekeeping theory in which I incorporate principles of graph theory and social network analysis, I describe the development of a more participatory but still asymmetrically structured networked gatekeeping process that is forming according to the communication infrastructure afforded by the internet and its associated technologies. In particular, this dissertation focuses on the implications of these developments for both the practice of and research about news diffusion, journalism, internet-mediated communication, and democracy. In an empirical study of the Twitter-based news ecology of a large Midwestern metropolitan area, I conduct a case study using primarily social network analysis methods that uncovers insights about the patterns that emerge within this dynamic participatory news construction and diffusion process. The findings of this dissertation can be useful for media scholars, media practitioners, and for anyone with an interest in understanding the evolution of the new media of the public sphere.en-USGatekeepingInternetJournalismNews diffusionsocial network analysisTwitterThesis or Dissertation