[talk] Public announcement games and question-answer games (Hans van Ditmarsch)

Time: 2016 Apr. 21, 15:30-17:00
Venue: Rm 301 XinZhai (新斋), Tsinghua University, Beijing.

Speaker: Hans van Ditmarsch (Laboratoire Lorrain de Recherche en Informatique et ses Applications)
Title: Public announcement games and question-answer games
[Joint work with: Thomas Agotnes, Johan van Benthem, Stefan Minica]
Abstract: We propose strategic games wherein the strategies either consist of players making public announcements (public announcement games) or consist of players asking each other questions and answering those questions (question-answer games). In a simplification of the question-answer game two players simultaneously ask each other a question that the opponent is then obliged to answer. The motivation for our research is to model conversation including the dynamics of questions and answers, and to provide new links between game theory and dynamic logics of information. Our main contributions for question-answer games are: the notion of a two-person question-answer game with information goals, the existence and computation of equilibria for these games, the correspondence with Bayesian games and their equilibria, and the existence of equilibria for positive goal formulae (a connection between logic and game theory). The results for public announcement games are fairly similar, but there are notable differences. For example, there is a maximally informative strategy in public announcement games (namely announce all you know), but there is no such thing as asking a question that will (always) elicit the maximally informative answer (you cannot know this). Further research involves generalizations to several rounds of questions and answers (or rounds of announcements), and to lying games wherein some communicated information may have the intention to deceive.

For more information:
– Agotnes, van Benthem, van Ditmarsch, Minica. Question-Answer Games. JANCL 21(3–4): 265–288, 2011.
– Agotnes, van Ditmarsch. What will they say? – Public announcement games. Synthese 179(s.-1): 57–85, 2011.

Tsinghua University – University of Amsterdam Joint Research Centre for Logic
北京市逻辑学会青年学者论坛 (Beijing Logic Forum For Young Scholars)
Department of Philosophy, Tsinghua University