Using a performative subsumption lattice to support commitment-based conversations

ABSTRACT

In this paper, we arrange FIPA's ACL performatives to form a sub-sumption lattice (ontology) and apply a theory of social commitments to achieve a simplified and observable model of agent behaviour. Using this model, it is straight forward to model agents' social commitments (obligations) based solely on observation of messages passed between the agents (such observation is supported by our agent infrastructure system). Furthermore, owing to the performatives being in a subsumption lattice, it is relatively easy for an observer to infer social commitment relationships even if the observer does not understand the details of messages or even the exact performatives used (so long as the observer has access to the performatives ontology).Although social commitment modelling of agent behaviour does not demand that agents are implemented using the social commitment model, our model nonetheless can be used in agent implementation to simplify the specification of agent behaviour through the use of "commitment operators" attached to the performatives (as policies) in the subsumption lattice.The primary contribution of this paper is to show how FIPA's performatives can be mapped onto a theory of social commitment to allow observable social behaviour and conformance to social norms.

REFERENCES

• 1: C. Castelfranchi. Commitments: From individual intentions to groups and organizations. In Proceedings of the First International Conference on Multi-Agent Systems, pages 41--48, San Francisco, CA, June 1995.
• 2: Antoni Diller, Z: An Introduction to Formal Methods, John Wiley & Sons, Inc., New York, NY, 1990
• 3: R. Flores. Modelling agent conversations for action. PhD thesis, Department of Computer Science, University of Calgary, June 2002.
• 4: Roberto A. Flores , Rob Kremer, Formal Conversations for the Contract Net Protocol, Proceedings of the 9th ECCAI-ACAI/EASSS 2001, AEMAS 2001, HoloMAS 2001 on Multi-Agent-Systems and Applications II-Selected Revised Papers, p.169-179, January 2002
• 5: R. Flores and R. Kremer. To commit or not to commit: Modelling agent conversations for action. Computational Intelligence, 18(2):120--173, 2003.
• 6: R. Flores and R. Kremer. Principled approach to construct complex conversation protocols. In The 17th Canadian Conference on Artificial Intelligence, Submitted.
• 7: N. Fornara and M. Colombetti. Operational specification of a commitment-based agent communication. pages 535--542.
• 8: Foundation for Intelligent Physical Agents (FIPA). FIPA ACL message structure specification. document number SC00061G, FIPA TC communication. http://www.fipa.org/specs/fipa00061/SC00061G.html, Dec. 2003.
• 9: Foundation for Intelligent Physical Agents (FIPA). FIPA communicative act library specification. document number SC00037J, FIPA TC communication. http://www.fipa.org/specs/fipa00037/SC00037J.html, Dec. 2003.
• 10: Erich Gamma , Richard Helm , Ralph Johnson , John Vlissides, Design patterns: elements of reusable object-oriented software, Addison-Wesley Longman Publishing Co., Inc., Boston, MA, 1995
• 11: J. Heard and R. Kremer. Detecting broken social commitments. In Workshop on Agent Communication, AAMAS'2005, Utrecht, The Netherlands, July 2005. AAMAS'2005.
• 12: R. Kremer, R. Flores, and C. LaFournie. Advances in Agent Communication, chapter A Performative Type Hierarchy and Other Interesting Considerations in the Design of the CASA Agent Architecture. LNAI. Springer Verlag, 2003. Available: http://sern.ucalgary.ca/kremer/papers/-AdvancesInAgentCommunication_KremerFlores-LaFournie.pdf.
• 13: P. Pasquier, M. Bergeron, and B. Chaib-draa. Diagal: A generic acl for open systems. In M.-P. Gleizes, A. Omicini, and F. Zambonelli, editors, ESAW, volume 3451 of Lecture Notes in Artificial Intelligence, pages 139--152. Springer Verlag, 2004.
• 14: Munindar P. Singh, Agent Communication Languages: Rethinking the Principles, Computer, v.31 n.12, p.40-47, December 1998 [doi>10.1109/2.735849]
• 15: D. Walton and E. Krabbe. Commitment in Dialogue: Basic Concepts of Interpersonal Reasoning. State University of New York Press, 1995.
• 16: Pinar Yolum , Munindar P. Singh, Flexible protocol specification and execution: applying event calculus planning using commitments, Proceedings of the first international joint conference on Autonomous agents and multiagent systems: part 2, July 15-19, 2002, Bologna, Italy [doi>10.1145/544862.544867]

INDEX TERMS

Primary Classification:
  I. Computing Methodologies
  I.2 ARTIFICIAL INTELLIGENCE
        I.2.11 Distributed Artificial Intelligence
            Subjects: Multiagent systems

Additional Classification:
  I. Computing Methodologies
  I.2 ARTIFICIAL INTELLIGENCE
        I.2.11 Distributed Artificial Intelligence
            Subjects: Coherence and coordination

General Terms:
Design, Experimentation, Standardization, Theory

Keywords:
ACL, CASA, FIPA, agent communications languages, performatives, policies, protocols, social commitments