Change in Quantitative Bipolar Argumentation: Sufficient, Necessary, and Counterfactual Explanations
This work addresses the need for formal explanations in argumentation systems, which is incremental as it builds on existing QBAF frameworks.
The paper tackles the problem of explaining changes in inference within Quantitative Bipolar Argumentation Frameworks by tracing strength inconsistencies to specific arguments, resulting in the identification of sufficient, necessary, and counterfactual explanations and a heuristic-based implementation.
This paper presents a formal approach to explaining change of inference in Quantitative Bipolar Argumentation Frameworks (QBAFs). When drawing conclusions from a QBAF and updating the QBAF to then again draw conclusions (and so on), our approach traces changes -- which we call strength inconsistencies -- in the partial order over argument strengths that a semantics establishes on some arguments of interest, called topic arguments. We trace the causes of strength inconsistencies to specific arguments, which then serve as explanations. We identify sufficient, necessary, and counterfactual explanations for strength inconsistencies and show that strength inconsistency explanations exist if and only if an update leads to strength inconsistency. We define a heuristic-based approach to facilitate the search for strength inconsistency explanations, for which we also provide an implementation.