REPRESENTING GEO-PRAGMATICS

Author:

Brodaric, Boyan

Graduate Program:

Geography

Degree:

Doctor of Philosophy

Document Type:

Dissertation

Date of Defense:

October 12, 2005

Committee Members:

Mark Gahegan, Committee Chair/Co-Chair
Alan Maceachren, Committee Member
William Ewart Easterling Iii, Committee Member
Frederico T Fonseca, Committee Member

Keywords:

GIScience
ontology
pragmatics
geoscience
knowledge discovery

Abstract:

Networks of logically defined concepts, known as ontologies, are being used as reference points for the meanings shared by digital messages in emerging cyber-based scientific information systems. This falls far short of the grander vision of such systems as a new operational paradigm for science, in which ontologies might aid knowledge discovery by serving as digital proxies for scientific knowledge. To enable scientific discovery, ontologies must additionally embrace the contextual knowledge evident in science, such as methodological histories, implicit assumptions, evolving concepts and diverse scientific perspectives. In this research, ontologies are considered digital instruments of scientific inquiry. A contextual theory of geoscientific ontology representation is developed, formalized, and tested against scientific practice and real data. The theory takes a geo-pragmatic viewpoint, in which discovery is facilitated through development of a computable formalism for elements of the geoscientific discovery process. The knowledge represented with the formalism can be tested and replicated by geoscientists, and have sufficient context to help stimulate new hypotheses. The formalism affects the structure and content of geoscientific ontologies: (1) concept structure is augmented by including origins, effects, uses, and their production functions; and (2) ontology content is affected by the introduction of situated concepts that are defined by unique geographical histories. The formalism is empirically tested by studying how geoscientists collaborate to develop a shared geologic map. The results are computationally implemented by using the formalism as a basis for a geospatial database schema in which the empirical data is hosted. This enables periods of geoscientific knowledge discovery and evolution to be explored visually. Geo-pragmatic influences are then used to help organize knowledge within the schema, through the introduction of several levels of abstraction for geoscience concepts including a level for situated concepts. These studies cumulatively show that geo-pragmatic representation is realistic, viable, and valuable, as it is shown respectively to fit geoscientific data and practice, be computationally implemented, and improve current geoscience knowledge representation practices.