An Ontological Hierarchy for Spatial Knowledge

Abstract

Knowledge in a complex domain may be orga-nized into an ontological hierarchy, in which each level provides a different description of the world and a different set of feasible inferences. We dis-cuss such a hierarchy for knowledge of large-scale space: the Spatial Semantic Hierarchy (SSH). We have used the SSH as the basis for our re-search on cognitive maps and robot exploration for many years. We illustrate by example how this knowledge-level hierarchy suggests a focused and productive set of research problems. 1 Ontological Hierarchies A robotic system interacting with an environment repre-sents knowledge about it, and performs inference about it,