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RAJENDRA SOOKDEO WALL, University of Massachusetts Amherst


This thesis examines the problem of the generation and evaluation of future world states in complex planning domains. A tool to aid plan formation in such domains, especially those containing uncontrolled agents, is presented. The tool is called a scenario: a collection of projections of future events, each of which is based on a set of assumptions about the behaviors, intentions and effects of the various processes involved. By examining the scenario generated for a planning problem the planner will be able to judge the potential futures and choose a course of action.^ The scenario is generated by performing categorical analysis on the planning problem under consideration: The total set of possible future states is in effect divided up into a set of classes or categories. This division is on the basis of the goals of the planner, the problem situation, the courses of action available to the planner to achieve the goals, and assumptions about the activities of the uncontrolled processes. For each category one or more examples are chosen to illustrate the kinds of events that could occur in that class of future world.^ Tree search of future states is avoided completely by generating the examples by retrieval and modification of experience. A knowledge base of previous experience in this domain is provided by an expert. When an example of a future world class is needed a memory of an experience with a similar problem is recovered from the knowledge base. The experience is modified to fit the current situation exactly and then used to illustrate the potentials of that future world class.^ This thesis then applies these ideas to two domains: errand running and conflict simulation games. A domain independent Tactical Assistant was built to perform categorical analysis and retrieval and modification of experience. Experiential knowledge bases were built for the two application domains to give advice on small tactical problems. ^

Subject Area

Computer science

Recommended Citation

WALL, RAJENDRA SOOKDEO, "THE THEORY AND USE OF SCENARIOS" (1983). Doctoral Dissertations Available from Proquest. AAI8310345.