# LIRa Session: Carlo Proietti

Speaker: Carlo Proietti

Date and Time: Thursday, June 7th 2018, 16:00-17:30

Venue: ILLC Seminar Room F1.15, Science Park 107.

Title: Group Polarization and Abstract Argumentation

Abstract: Discussion often makes individuals more radical about their initial opinion. This phenomenon is known as  Group-induced Attitude Polarization (Moscovici et al. 1969). A byproduct of it are bipolarization effects, where the distance between the opinions of two groups increases after discussion. A fine-grained analysis of the exchange of information among agents in a debate is key to understand how such dynamics unfold. I use Argumentation Graphs as a tool for encoding the information of agents in a debate. Measures of the degree of acceptability of an opinion in a graph are introduced to illustrate how polarisation is induced by exchange of arguments among agents. I also show that different policies of information transmission and update have a decisive impact on polarization and bipolarization effects.