A knowledge framework for representing, manipulating and reasoning with geographic semantics

Abstract

This paper describes a programmatic framework for representing, manipulating and reasoning with geographic semantics. The framework enables visualizing knowledge discovery, automating tool selection for user defined geographic problem solving, and evaluating semantic change in knowledge discovery environments. Methods, data, and human experts (our resources) are described using ontologies. An entity’s ontology describes, where applicable: uses, inputs, outputs, and semantic changes. These ontological descriptions are manipulated by an expert system to select methods, data and human experts to solve a specific user-defined problem; that is, a semantic description of the problem is compared to the services that each entity can provide to construct a graph of potential solutions. A minimal spanning tree representing the optimal (least cost) solution is extracted from this graph, and displayed in real-time. The semantic change(s) that result from the interaction of data, methods and people contained within the resulting tree are determined via expressions of transformation semantics represented within the JESS expert system shell. The resulting description represents the formation history of each new information product (such as a map or overlay) and can be stored, indexed and searched as required. Examples are presented to show (1) the construction and visualization of information products, (2) the reasoning capabilities of the system to find alternative ways to produce information products from a set of data methods and expertise, given certain constraints and (3) the representation of the ensuing semantic changes by which an information product is synthesized.