SODAS Pop-up Talk w/ Pantelis Pipergias Analytis

Pantelis P. Analytis is an Assistant Professor at the Danish-IAS at the University of Southern Denmark (SDU). Before joining the University of Southern Denmark he worked as a predoctoral researcher at the Max Planck Institute for Human Development in Berlin and as a postdoctoral researcher at the Computer and Information Science departments at Cornell University in Ithaca. He has a background in economics and cognitive psychology and is self-taught in machine learning, computational social science and a few other disciplines.  In his research, Pantelis develops mathematical and computational models of individual and collective behavior and uses experiments, big-data and large-scale simulations to assess their descriptive and prescriptive value. 

The structure of social influence in recommender networks

The ability of people to influence the opinion of others on matters of taste varies greatly---both in the offline world and in recommender systems. What are the mechanisms underlying this striking inequality? We use the weighted k-nearest-neighbor algorithm to represent an array of social learning strategies and show---using network theory---how this gives rise to networks of social influence in six real-world domains of taste. By doing so, we show three novel results that apply both to offline advice taking and online recommender settings. First, influential individuals have mainstream tastes and high dispersion in their taste similarity with others. Second, the fewer people an individual or algorithm consults (i.e., the lower k) and the more sensitive an individual or algorithm is to how similar other people are, the smaller the group of people with substantial influence. Third, the influence networks that emerge are hierarchically organized. Our results shed new light on classic empirical findings in communication and network science and can help improve our understanding of social influence in the offline and online world. 

The SODAS Pop-up Talk will take place at SODAS in building 1, 2nd floor, room 26 (1.2.26) of the CSS Campus, University of Copenhagen, from 9:00 am - 10:00 am Wednesday the 26th of February 2020.

If you have questions or want to know more, please write Sophie Smitt Sindrup Grønning at