On the sources of complexity in agent design

This article addresses the question of what makes agent design hard. This is a fundamental issue not just for the intelligent agents community, but also for the computer science and software engineering communities in general. The article begins by presenting a simple, informal model of agents and their environments, and then uses this model to frame a discussion on the sources of complexity in agent design. Three key sources of complexity are identified: the agent's environment, the nature of interaction between agent and environment, and the nature of the specification or task for the agent. Following this discussion, the article presents a simple formal model of agents and their environments, which is capable of representing many of these sources of complexity. Using the formal model, a number of stereotypical agent design problems are defined. The article concludes with a discussion of related work and issues.