22 November 2021
On Monday, November 22, 6-7pm, our MSc programme will have the pleasure and honor of hosting online Evimaria Terzi, Professor and Associate Chair of Academics at the Computer Science Department of Boston University in USA, who will give an invited lecture on “Measuring and Moderating Opinion Polarization in Social Networks”.
Abstract: The polarization of society over controversial social issues has been the subject of study in social sciences for decades. The widespread usage of online social networks and social media, and the tendency of people to connect and interact with like-minded individuals has only intensified the phenomenon of polarization. In this talk, we will consider the problem of measuring and reducing polarization of opinions in a social network. Using a standard opinion formation model defined by Friedkin and Johnsen in the 1990s, we will define the polarization index, which, given a network and the opinions of the individuals in the network, aims to quantify the polarization observed in the network. Our measure captures the tendency of opinions to concentrate in network communities, creating echo-chambers. Given this numeric measure of polarization, we will then discuss the problem of reducing polarization in the network by convincing individuals (e.g., through education, exposure to diverse viewpoints, or incentives) to adopt a more neutral stand towards controversial issues. By exploiting the linear-algebraic characteristics of the opinion formation model we will show how to design polynomial-time approximation algorithms for this problem and demonstrate the efficiency and the effectiveness of those algorithms in real data.
Bio: Prof. Evimaria Terzi is a Professor and Associate Chair of Academics in the Department of Computer Science at Boston University. Prof. Terzi has obtained her PhD from the University of Helsinki in Finland, her MSc from Purdue University and her BSc from the Dept of Informatics at Aristotle University of Thessaloniki. Prior to joining BU in 2009, Prof. Terzi was a Research Staff Member at IBM Almaden Research Center. Prof. Terzi’s research interests are in the general area of algorithmic data mining with emphasis on recommender systems, online social systems, team formation and, most recently, ride hailing platforms. Her work is funded by NSF and company gifts (such as Google, Microsoft and Amazon).