Integrating Information from Disparate Contexts: A Theory of Semantic Interoperability

Current technology (e.g. the Internet) has provided vast opportunities to link many information sources (e.g. databases) to many information receivers (e.g. users and applications). This link, however, provides mainly for physical interoperability. There still remains major difficulties in achieving semantic interoperability. Semantic interoperability means that sources and receivers can exchange information in a meaningful manner. Ensuring semantic interoperability is difficult when sources and receivers have different contexts. That is, receivers have preferences, goals and assumptions about how to ask questions and interpret answers. Sources, that have been independently created and maintained, can have a different set of underlying assumptions, and which are reflected in the way their information is organized and presented. Receivers may therefore encounter serious difficulties when interacting with the variety and multiplicity of distributed, autonomous sources. In general terms, this thesis is concerned with the development of intelligent systems that will facilitate semantic interoperability between sources and receivers, without violating their contexts, allowing them to continue functioning "as usual". More specifically, this thesis has three components. The first component draws upon the philosophical disciplines of Semantics and Ontology for insights into the nature of semantic interoperability. In the second component, these insights are integrated into a formal definition of a semantically interoperable system based on the Context Interchange Architecture. This definition is an abstract specification which represents a conceptualization of semantic interoperability. It is a formal statement of what a Context Interchange system should deliver and provides a rigorous basis for an implementation. In the third and final part of this thesis, a system, which realizes this specification, is developed to serve as a proof of concept and to illustrate various aspects of the theory developed in this thesis. Thesis Committee: Professor Stuart E. Madnick (Chair) Dr. Michael D. Siegel Professor Yair Wand