Multi-agent systems (MAS) offer an approach to solve complex problems where data and control are inherently distributed among several agents. Normally, agents have to cope with conflicts based on inconsistent knowledge which arise when they exchange information. A relative common alternative to solve these conflicts is Argumentation. This technique allows agents to develop a coordination process based on the exchange of justifications supporting a piece of knowledge, with the aim of proving its validness. However, most argumentation frameworks are theoretical approaches to this problem. We have developed an Argumentation System Based on Ontologies (ASBO). It follows an engineering-oriented approach to materialize a software architecture which allows working with argumentation in MAS. Moreover, ASBO has also a formal model in the background. This paper introduces such formal model, in order to identify and unambiguously define the core elements that argumentation systems should include.
Multi-agent systems engineering; Knowledge management; Argumentation; Persuasion dialogs