19 September 2018, Computational Social Choice Seminar, Weiwei Chen
Abstract argumentation frameworks are a convenient means for modelling different arguments and their relationships to each other. When confronted with such an abstract argumentation framework, different agents may disagree on which arguments to accept, i.e., they may choose different so-called extensions. In the context of designing systems to support collective argumentation, we may then wish to aggregate such alternative extensions into a single extension that appropriately reflects the views of the group as a whole. Focusing on a conceptually and computationally simple family of aggregation rules, the quota rules, in this talk I will discuss under what circumstances relevant properties of extensions shared by all extensions reported by the individual agents will be preserved under aggregation. The properties considered are some of the classical properties of argumentation semantics, such as being a conflict-free, a complete, or a preferred extension. While for some of these properties there are quota rules that guarantee their preservation, for the more demanding properties it is impossible to do so in general. This is joint work with Ulle Endriss.
No specialist knowledge in either abstract argumentation theory or social choice theory will be required to follow this talk.