Handling Inconsistency with Preference-Based Argumentation

Argumentation is a promising approach for handling inconsistent knowledge bases, based on the justification of plausible conclusions by arguments. Due to inconsistency, arguments may be attacked by counterarguments. The problem is thus to evaluate the arguments in order to select the most acceptable ones. The aim of this paper is to make a bridge between the argumentation-based and the coherence-based approaches for handling inconsistency. We are particularly interested by the case where priorities between the formulas of an inconsistent knowledge base are available. For that purpose, we will use the rich preference-based argumentation framework (PAF) we have proposed in an earlier work. A rich PAF has two main advantages: i) it overcomes the limits of existing PAFs, and ii) it encodes two different roles of preferences between arguments (handling critical attacks and refining the evaluation of arguments). We show that there exist full correspondences between particular cases of these PAF and two well known coherence-based approaches, namely the preferred sub-theories and the democratic as well.