© SCS MODELING NORMS IN ELECTRONIC INSTITUTIONS Frank Dignum Ismail Khalil Ibrahim Edgar Weippl Wieland Schwinger dignum@cs.uu.nl ismail@cs.uu.nl edgar.weippl@scch.at wieland.schwinger@scch.at Utrecht University University of Ghent Netherlands Software Competence Center Hagenberg Hauptstr. 99, A-4232 Hagenberg Austria KEYWORDS Agents, Multi agent systems, Norms, Cooperation ABSTRACT Two approaches have been advocated for the design and modeling of (social) norms in multi agent systems: in the coordination strategy, multi agent systems are defined as a set of entities regulated by mechanisms of social order and created by more or less autonomous actors to achieve common goals; in the cooperation strategy, agents model specific roles in the society and interact with each other as means to accomplish their goals. In this paper, we argue that there is a relative duality between the two approaches with respect to their use of norms as constraints on the social behavior of multi agents systems. We present and discuss a variant of an existing framework for modeling multi agent systems in an environment governed by norms for the cooperation strategy. INTRODUCTION Institutions, Norms and Multi-Agent Systems The study and modeling of norms has attracted the interest of scientists from different disciplines such as sociology, economics, psychology, and computer science. According to Encyclopedia Britannica, norms are rules or standards of behavior shared by members of a social group. Several researchers have recognized that the design of agent societies can benefit from abstractions analogues to those employed by our robust and relatively successful societies and organizations [11]. There is a growing body of work that touches upon the concepts of norms and institutions in the context of multi agent systems [11, 12]. Human interactions very often follow conventions [12] that is, general agreements on language, meaning and behavior. By following conventions humans decrease uncertainties about the behavior of others, reduce conflicts of meaning, create expectations about the outcome of the interaction and simply the decision process by restricting to a limited set the potential actions that may be taken. These benefits explain why conventions have been so widely used in many aspects of human interaction: trade, law, games, etc., In most societies, norms are backed by a variety of social institutions [11] that enforce law and order (e.g., courts, police), monitor for and respond to emergencies (e.g., ambulance system), prevent and recover from unanticipated disasters (e.g., coast guard, fire-fighters), etc., The benefit of an institution resides in its potential to lend legitimacy and security to its members by establishing norms. In this way civilized societies allow citizens to utilize relatively simple and efficient rules of behavior, offloading the prevention and recovery of many problem types to social institutions that can handle them efficiently and effectively by virtue of their economies of scale and widely accepted legitimacy. Successful civil societies have thus achieved a division of labor between individuals and institutions that decreases the barriers to survival for each citizen, while helping increase the welfare of the society as a whole. The electronic counterpart of the physical institution does a similar task for software agents: it can engender trust through certification of an agent and by the guarantees that it provides to back collaboration [9, 10, 11, 12]. However, the electronic institution can also function as the independent place, in which all types of agent independent information about the interaction between the agents within the society is stored e.g., it defines the message types that can be used by the agents in their interactions, the rules of encounter, etc., In general, institutions enable to 1) specify the coordination structure that is used, 2) describe exchange mechanisms of the agent society, 3) determine interaction and communication forms within the agent society, 4) facilitate the perception of individual agents of the aims and norms of an agent society and 5) enforce the organizational aims of the agent society.