G. Wasson and W. Martin
Actions and objects are closely tied together. We often think of the actions we can perform on objects as properties of those objects. The theory of action presented here, contains the belief that actions are defined in terms of the objects they effect. Intuitively then, actions consist of a verb and a noun, for example, pick-up-the-soda-can, go-to-the-car, or paint-the-canvas. We are interested in two different roles for nouns, as direct objects which the agent manipulates (the-can in pick-up-the-can) and as indirect objects which specify destinations (the-cat in go-to-thecar). We refer to these nouns as m-role objects or d-role objects. In our theory of action, before performing any action, an agent first develops a deietic representation of the m-role or d-role object. So, the agent identifies the-soda-can, the-car, or the-canvas. When this is completed, the specified action can be taken using the object indicated by the representation. A plan is, therefore, a set of objects and the actions to perform. We contend that this deictic organization is an effective means of expressing actions because an action cannot take place without identifying the m or d-role objects. Our research will show that actions can be performed effectively and plans can be organized appropriately using such a representation. We will present a system that uses deictie representations as a means to integrate a deliberate planner and a perception/action system. Non-local-space information in the plans will be conveyed to the perception/action system, where it can be acted on. Emergent from our theory of activity is a representation system that integrates agent control system components. Our theory is centered on the real world objects effeeted by action. We believe this provides sufficient and effective organizing principles for designing perception/action systems.