University of Oxford
Wednesday 11th June 2014, 1:45pm
TITLE | Using simple social mechanisms to understand collective online behaviour
ABSTRACT | Human activities increasingly take place in online environments, providing novel opportunities for relating individual behaviours to population-level outcomes. In my talk I will consider a simple generative model for the collective behaviour of millions of social networking site users who make choices between different software applications that they can install. The proposed model incorporates two distinct social mechanisms: (1) imitative behaviour reflecting the influence of recent installation activities of other users; (2) rich-get-richer popularity dynamics where users are influenced by the cumulative popularity of each application. Interestingly, although various combinations of the two mechanisms yield long-time behaviour that is consistent with data, the only models that reproduce the observed temporal dynamics are those that strongly emphasize the recent installation activities of other users over their cumulative popularity. More generally this demonstrates that even when using purely observational data, as opposed to experimental research designs, temporal data-driven modelling can in fact effectively distinguish between competing microscopic mechanisms, providing novel insights into collective online behaviour
BIOGRAPHY | Felix Reed-Tsochas is the James Martin Lecturer in Complex Systems and Associate Dean of Research at the Saïd Business School, where he also directs the CABDyN Complexity Centre. He leads the Oxford Martin Programme on Complexity, Risk and Resilience at the Oxford Martin School, and together with Doyne Farmer directs the Programme in Complexity Economics that is part of the Institute for New Economic Thinking (INET) at the Oxford Martin School. His research interests, informed by a background in condensed matter physics, broadly focus on the structure and dynamics of complex networks, including social networks, financial networks, ecological networks, and supply networks. One overarching question that integrates many of the research projects that he and his group are working on is how collective behaviours and structures in groups and populations can be related to the decisions and actions of individual agents or actors.