TitleCombining social choice theory and argumentation: Enabling collective decision making
Publication TypeJournal Article
Year of Publication2019
AuthorsGanzer-Ripoll J, Criado N, López-Sánchez M, Parsons S, Rodríguez-Aguilar JA
JournalGroup Decision and Negotiation
Date Published02/2019
KeywordsArgumentation, multiagent systems, Social choice

Argumentation-based debates are a powerful tool for resolving conflicts and reaching agreements, and they have great potential in open environments such as on-line communities. Here we provide some of the computational infrastructure to support argumentation-based debates, in particular focusing on the problem of how participants in a debate can reach agreement about the outcome of the debate, given all the statements that have been made. Our approach permits the representation of the arguments made by the participants involved in a debate, allows both positive and negative relationships between the arguments to be represented, and makes it possible for participants to express opinions about both the arguments and the outcome of the debate. Our main contribution is in providing the first solution to the problem of computing a collective decision from participants' opinions about the arguments in (and the outcome of) the debate. With this aim, we investigate the use of a family of aggregation functions. This family starts with a function that is firmly rooted in the social choice literature, and is extended with functions that are more oriented towards the use of argumentation. We find that to ensure that the collective decision is coherent, a property that we think is essential, an aggregation function needs to take into account the dependencies between arguments.
We also provide an empirical analysis of the performance of our approach to reaching a collective decision, showing that a collective decision can be reached for debates, of the size that one currently finds online, in reasonable time.