Compromise in Negotiation: Exploiting Worth Functions over States

Previous work 32, 33, 35, 37] discussed inter-agent negotiation protocols. One of the main assumptions there was that the agents' goals remain xed|the agents cannot relax their initial goals, which can be achieved only as a whole and cannot be partially achieved. A goal there was considered a formula that is either satissed or not satissed by a given state. We here present a more general approach to the negotiation problem in non-cooperative domains where agents' goals are not expressed as formulas, but rather as worth functions. An agent associates a particular value with each possible nal state; this value reeects the degree of satisfaction the agent derives from being in that state. With this new deenition of goal as worth function, an agreement may lead to a situation in which one or both goals are only partially achieved (i.e., agents may not reach their most desired state). We present a negotiation protocol that can be used in a general non-cooperative domain when worth functions are available. This multi-plan deal type allows agents to compromise over their degree of satisfaction, and (in parallel) to negotiate over the joint plan that will be implemented to reach the compromise nal Some material in this paper appeared in preliminary form in 36]. 1 state. The ability to compromise often results in a better deal, enabling agents to increase their overall utility. Finally, we present more detailed examples of speciic worth functions in various domains, and show how they are used in the negotiation process.