Representing " Place " in a Frame System

This thesis explores hierarchy as a knowledge representation strategy. I will examine the use of hierarchy to represent knowledge about place, a natural candidate given the importance of the inclusion relationship between places. I shall show that for a. first order theory of place, hierarchy proves economical and powerful, effectively expressing regularities of place implicit in statements such as "Boston is in Massachusetts" and "Cambridge is a city". But I shall also show that for an extended theory of place knowledge, hierarchy proves insufficient, burdened by the handling of incomplete, uncertain, and exceptional information, and the effects of data addition and deletion. Finally, I shall propose methods by which a hierarchical representation scheme can cope with dynamic knowledge bases in an interactive environment, an essential capability for the practical use of such representations. Thesis Supervisor: Ira P. Goldstein Title: Associate Professor of Electrical Engineering and Computer Science Kepresenting. Place MarK ay jerrery