On April 16th, Gabriella Pigozzi (LAMSADE, Université Paris-Dauphine) is invited in the seminar of the team Décision, Rationalité, Interaction (IHPST) (from 5.00 to 7.00 pm, seminar room of the department of cognitive studies of École Normale Supérieure, 29 rue d’Ulm, 75005 Paris). The title of her presentation will be “A Framework for Norm Change” (joint work with Leon van der Torre, Université du Luxembourg)
Abstract: The focus of this talk is the social/organizational structure of a multiagent system, and in particular norms and normative behavior. Normative systems must be able to evolve over time, for example due to actions creating or removing norms in the system. The only formal framework to evaluate and classify normative system change methods is the so-called AGM framework of theory change, which has originally been developed as a framework to describe and classify both belief and normative system change. However, it has been used for belief change only, since the beliefs or norms are represented as propositional formulas. We take AGM theory change as a framework to evaluate the dynamics of rule based systems, to replace propositional formulas in the AGM framework of theory change by pairs of propositional formulas, representing the rule based character of norms, and to add several principles from the input/output logic framework. In this new framework, we show that results from belief base dynamics can be transferred to rule base dynamics, but that a similar transfer of AGM theory change to rule change is much more problematic.