EPJ Data Sci. (2014) 3: 32
https://doi.org/10.1140/epjds/s13688-014-0032-y

Regular article

The emergence of roles in large-scale networks of communication

¹ Annenberg School for Communication, University of Pennsylvania, Philadelphia, USA
² Oxford Internet Institute, University of Oxford, Oxford, UK
³ Qatar Computing Research Institute, Qatar Foundation, Doha, Qatar

^* e-mail: sgonzalezbailon@asc.upenn.edu
^** e-mail: jborge@qf.org.qa

Received: 10 April 2014
Accepted: 23 October 2014
Published online: 7 November 2014

Abstract

Communication through social media mediates coordination and information diffusion across a range of social settings. However, online networks are large and complex, and their analysis requires new methods to summarize their structure and identify nodes holding relevant positions. We propose a method that generalizes the sociological theory of brokerage, originally devised on the basis of local transitivity and paths of length two, to make it applicable to larger, more complex structures. Our method makes use of the modular structure of networks to define brokerage at the local and global levels. We test the method with two different data sets. The findings show that our approach is better at capturing role differences than alternative approaches that only consider local or global network features.