General Purpose Database of Knowledge about Actions

University Of Texas At Austin, Austin TX

Investigators

Abstract

The objective of this project is to build a general purpose database of commonsense facts about actions expressed in the language of the Causal Calculator (CCalc). CCalc is a system for automated reasoning about actions and for plan generation. Its language has been used to formalize many small action domains, such as the blocks world and the Missionaries and Cannibals puzzle, and also several medium-size domains, such as Sandewall's Zoo World. Building a general purpose database of knowledge about actions will be a step towards solving the problem of generality in knowledge representation. Building on past efforts, this project will isolate the concepts and principles that these and similar individual domains have in common, and build a database of such principles stated in a general form. The creation of such a data base will make it possible to obtain formalizations of many individual action domains, including those studied in the past, by adding domain-specific facts. The database will include general assumptions about the effects, both direct and indirect, of actions of various kinds, about the executability of actions, and about agents that execute them. Some of these facts have to do with objects and change in their locations and internal states. For instance, one useful assumption is that normally an agent can execute an action affecting the location or state of an object only if the agent is located next to the object. Another is that an object is typically supported by something--by horizontal surfaces of some kind, or by other objects supported by such a surface--and that moving the object indirectly affects the locations of the things that are supported by that object. The database will also contain commonsense facts about creating and destroying objects, about animals and humans, about buying and selling, about actions related to knowledge and memory, etc.