Pareto optimality and strategy-proofness in group argument evaluation

摘要

An inconsistent knowledge base can be abstracted as a set of arguments and a defeat relation\udamong them. There can be more than one consistent way to evaluate such an argumentation\udgraph. Collective argument evaluation is the problem of aggregating the opinions\udof multiple agents on how a given set of arguments should be evaluated. It is crucial not\udonly to ensure that the outcome is logically consistent, but also satisfies measures of social\udoptimality and immunity to strategic manipulation. This is because agents have their individual\udpreferences about what the outcome ought to be. In the current paper, we analyze three\udpreviously introduced argument-based aggregation operators with respect to Pareto optimality\udand strategy-proofness under different general classes of agent preferences. We highlight\udfundamental trade-offs between strategic manipulability and social optimality on one hand,\udand classical logical criteria on the other. Our results motivate further investigation into the\udrelationship between social choice and argumentation theory. The results are also relevant\udfor choosing an appropriate aggregation operator given the criteria that are considered more\udimportant, as well as the nature of agents’ preferences.