Project description

In this project, we will investigate the problem of argumentative reasoning in logic-based formalisations of knowledge, where the specified information is flawed in terms of non-existence of non-trivial conclusions. We will consider the formal framework of abstract argumentation and the notion of vacuity that characterises such flawed situations. More precisely, an abstract argumentation framework is vacuous (wrt. some given semantics) if there exists no non-empty set of acceptable arguments. This project will deeply investigate the notion of vacuity and develop methods to handle it. In particular, we will develop new argumentation semantics, methods for explaining vacuity as well as measuring it, and introduce initial sets and serialisation sequences for such cases that will help to point out to the exact issues in the represented knowledge. While we will mainly focus on the formalism of abstract argumentation, we will also apply the newly developed concepts to generalisations of abstract argumentation frameworks, in particular bipolar argumentation frameworks, argumentation frameworks with recursive attacks, and argumentation frameworks with collective attacks, and also to structured formalisms, in particular ASPIC+.

Project leader

• Matthias Thimm, University of Hagen

People

• Lydia Blümel, University of Hagen

Publications

• Lydia Blümel, Matthias Thimm. Revisiting Vacuous Reduct Semantics for Abstract Argumentation. In Proceedings of the 27th European Conference on Artificial Intelligence (ECAI'24). October 2024. bibtex pdf
• Lydia Blümel, Matthias Thimm. Approximating Weakly Preferred Semantics in Abstract Argumentation through Vacuous Reduct Semantics. In Proceedings of the 20th International Conference on Principles of Knowledge Representation and Reasoning (KR'23). September 2023. bibtex pdf
• Matthias Thimm. On Undisputed Sets in Abstract Argumentation. In Proceedings of the 37th AAAI Conference on Artificial Intelligence (AAAI'23). February 2023. bibtex pdf