An Approach to Operationalize Regulative Norms in Multiagent Systems

Abstract

Multiagent systems have emerged as a promising approach to develop information systems that clearly require several goal-oriented problem-solving entities [Jennings et al., 1998]. Following this direction, it is believed that upcoming information systems will be implemented as open multiagent systems, in which agents (their entities) can freely migrate among those systems in order to obtain resources or services not found locally. A multiagent system(s) (hereinafter referenced as MAS1) is/are an example of an open system in which the actions of heterogeneous, self-interested agents may deviate from the expected behavior in a context. Openness has led to dynamic software systems that have no centralized control and that are composed of autonomous entities [Hewitt, 1991]. Key characteristics of such systems are heterogeneity, conflicting individual goals and limited trust [Artikis et al., 2002]. As stated in [Esteva et al., 2004], “openness without control may lead to chaotic behavior”. In order to be a viable solution for dynamic software systems, MAS must be enhanced with norms for defining which actions are permitted, obliged and prohibited to be performed by agents so that the system does not reach an undesirable state. A permitted norm defines that an action is allowed to be performed; an obliged norm defines that an action must be performed; and, a prohibited norm defines that an action must not be performed. Permissions and prohibitions are used to describe positive/negative authorizations, whereas obligations are used to describe responsibilities [Kagal and Finin, 2007]. These three types of norms represent the three fundamental deontic statuses of an action [Alberti et al., 2006] from deontic logic [Wright, 1951] and they are logically connected as presented by the following statements: If an action is permitted, then, it is not prohibited; If an action is obligatory, then, it is permitted and it is not prohibited; If an action is prohibited, then, it is not obligatory and it is not permitted;