Four papers and a demo presentation accepted at COMMA 2022


The members of AIG have successfully submitted four papers and a demo presentation to the 9th International Conference on Computational Models of Argument, COMMA 2022 in Cardiff, Wales.

Abstracts of the papers and the demo presentation


A Ranking Semantics for Abstract Argumentation based on Serialisabilty

by Lydia Blümel and Matthias Thimm

Abstract: We revisit the foundations of ranking semantics for abstract argumentation frameworks by observing that most existing approaches are incompatible with classical extension-based semantics. In particular, most ranking semantics violate the principle of admissibility, meaning that admissible arguments are not necessarily better ranked than inadmissible arguments. We propose new postulates for capturing said compatibility with classical extension-based semantics and present anew ranking semantics that complies with these postulates. This ranking semanticsis based on the recently proposed notion of serialisability that allows to rank arguments according to the number of conflicts needed to be solved in order to include that argument in an admissible set.

On the Impact of Data Selection when Applying Machine Learning in Abstract Argumentation

by Isabelle Kuhlmann, Thorsten Wujek and Matthias Thimm

Abstract: We examine the impact of both training and test data selection in machine learning applications for abstract argumentation, in terms of prediction accuracy and generalizability. For that, we first review previous studies from a data-centric perspective and conduct some experiments to back up our analysis. We further present a novel algorithm to generate particularly challenging argumentation frameworks wrt. the task of deciding skeptical acceptability under preferred semantics. Moreover, we investigate graph-theoretical aspects of the existing datasets and perform some experiments which show that some simple properties (such as in-degree and out-degree of an argument) are already quite strong indicators of whether or not an argument is skeptically accepted under preferred semantics.

Serialisable Semantics for Abstract Argumentation

by Lars Bengel and Matthias Thimm

Abstract: We investigate the recently proposed notion of serialisability of semantics for abstract argumentation frameworks. This notion describes semantics where the construction of extensions can be serialised through iterative addition of minimal non-empty admissible sets. We investigate general relationships between serialisability and other principles from the literature. We also investigate the novel unchallenged semantics as a new instance of a serialisable semantics and, in particular, analyse it in terms of satisfied principles and computational complexity.

Ordinal Conditional Functions for Abstract Argumentation

by Kenenth Skiba and Matthias Thimm

Abstract: We interpret and formaliseordinal conditional functions (OCFs) in abstract argumentation frameworks based on ideas and concepts defined for conditional logics. There, these functions are used to rank interpretations, and we adapt them to rank extensions instead. Using conflict-freeness and admissibility as two essential principles to define the semantics of OFCs, we obtain a framework that allows to rank sets of arguments wrt. their plausibility. We analyse the properties of this framework in-depth, and in doing so we establish a formal bridge betweenthe approaches of abstract argumentation and conditional logics.

Demo presentation:

probo2: A Benchmark Framework for Argumentation Solvers

by Jonas Klein and Matthias Thimm

We introduce probo2, an end-to-end benchmark framework for abstract argumentation solvers. It offers evaluation capabilities and analysis features for a wide range of computational problems and is easily customizable.