September 22nd at 18:00, in F1.15
How can we aggregate individual opinions to obtain a single such that reflects the consensus of a group? In this talk, I will address this question by introducing the problem of aggregation of argumentation frameworks (AF) and presenting a new approach to it in the light of graph aggregation. First, I will discuss a survey on the topic by Coste-Marquis et al., which focuses on aggregation rules that minimise the distance between AFs. Then, I will demonstrate Endriss and Grandi’s work, which is concerned with desirable axiomatic properties of aggregation rules.
Finally, I will present our recent research, where we study the preservation of semantic properties during the aggregation of AFs. We show under what circumstances semantic properties (such as acyclicity, the acceptability of an argument) of AFs agreed upon by the individual agents can be preserved under aggregation. Our results range from ones that indicate what kind of aggregation rule can satisfy certain combinations of desiderata, to impossibility results that show that only dictatorships can preserve the most demanding semantic properties.