Visual Explanations for the Verification Problem in Abstract Argumentation

The verification problem in abstract argumentation consists of checking whether a set is acceptable under a given semantics in a given argumentation graph. Explaining why the answer is so is the challenge tackled by this paper. Visual explanations in the form of subgraphs of the initial argumentation framework are defined. These explanations are grouped into classes, allowing one to select the explanation that suits them best among the several offered possibilities. Results are provided on how to use the visual aspects of these explanations to support the acceptability of a set of arguments under a semantics. Computational aspects of specific explanations are also investigated.