On the Mutability of Protocols

The task of developing a framework for which agents can communicate reliably and flexibly in open systems is not trivial. This thesis addresses the dichotomy between reliable communication and facilitating the autonomy of agents to create more flexible and emergent interactions. By the introduction of adaptations to a distributed protocol language, agents benefit from the ability to communicate interaction protocols to elucidate the social norms (thus creating more reliable communication). Yet, this approach also provides the functionality for the agent to unilaterally introduce new paths for the conversation to explore unforeseen opportunities and options (thus restoring more autonomy than possible with static protocols). The foundation of this work is Lightweight Coordination Calculus (LCC). LCC is a distributed protocol language and framework in which agents coordinate their own interactions by their message passing activities. In order to ensure that adaptations to the protocols are done in a reasonable way, we examine the use of two models of communication to guide any transformations to the protocols. We describe the use of FIPA’s ACL and ultimately its unsuitability for this approach as well as the more fecund task of implementing dialogue games, an model of argumentation, as dynamic protocols. The existing attempts to develop a model that can encompass the gulf between reliability and autonomy in communication have had varying degrees of success. It is the purpose of the research described in this thesis to develop an alloy of the various models, by the introduction of dynamic and distributed protocols, to develop a framework stronger than its constituents. Though this is successful, the derivations of the protocols can be difficult to reconstruct. To this end, this thesis also describes a method of protocol synthesis inspired by models of human communication that can express the dialogues created by the previous approaches but also have a fully accountable path of construction. Not only does this thesis explore a unique and novel approach to agent communication, it is grounded in a practical implementation. iii Acknowledgements Nothing of worth is created inside a vacuum. The worth of this document has yet to be determined but if there is any success and insight found within, the responsibility of its creation cannot be mine alone. There are numerous people who have given me assistance in its creation: from friends and acquaintances who during casual chats unintentionally sparked some new idea, to my supervisors who have patiently guided me through the PhD process. I fear any enumeration of the people who deserve acknowledgement will inevitably be incomplete. Yet, two individuals have made a huge impact upon the completion of this thesis by their, for lack of a better phrase, academic midwifery. David Robertson and Chris Walton have been the best supervisors both in wisdom and temperament. To all my fellow research students, especially the men of the four one five, who have at one time dotted my i’s and crossed my t’s as well as paused their own work so that I could discuss with them my own. I would like also thank my family for the continual support that I have received throughout my education. It is my family who is most responsible for enabling me to complete my undergraduate degree and providing me with the opportunity to strive for the goal to which this thesis is a testament. I sincerely thank all of you.