Aggregation in Value-Based Argumentation Frameworks

Abstract

Value-based argumentation enhances a classical abstract argumentation graph -in which arguments are modelled as nodes connected by directed arrows called attacks -with labels on arguments, called values, and an ordering on values, called audience, to provide a more fine-grained justification of the attack relation. With more than one agent facing such an argumentation problem, agents may differ in their ranking of values. When needing to reach a collective view, such agents face a dilemma between two equally justifiable approaches: aggregating their views at the level of values, or aggregating their attack relations, remaining therefore at the level of the graphs. We explore the strenghts and limitations of both approaches, employing techniques from preference aggregation and graph aggregation, and propose a third possibility aggregating rankings extracted from given attack relations.

Aggregating Bipolar Opinions through Bipolar Assumption-based Argumentation

“…We follow the latter approach, focusing specifically on BAFs and, at the same time, a simple form of structured argumentation frameworks: Bipolar ABA. Other approaches have instead focused on aggregating argumentation frameworks in the other forms, specifically AAFs [CE17, BTA17b, ABTR17, CE18, DKV18, CE19]) and the extensions thereof [CE18], value-based argumentation [LDG19], and abstract dialectical frameworks [Boo15]. We adopt the view that aggregation takes place by means of rules drawn from Social Choice Theory, e.g.…”