Wednesday, July 28, 2010
Ontologies of what?
Following the common definition of ontology by Gruber, perhaps more precisely worded by Guarino, ontologies are formalization of concepts. Everybodies experience and ample experimental results show that concepts have a radial structure and are influenced by the context. The concept of "pet" is different when the context is "running in the garden" (prototype dog or cat), "the name of my daughter's pet when she was 3 was Bella" (stuffed animal) or "Peter's pet is swimming in the pond" (goldfish).
What is the context implied when a concept is formalized in an ontology? Are we tacitly assuming that no context is affecting the concept? Aerts, Rosch and Gabora (2008) posit a "ground state" for a concept, which is the state the concept is in before any context is operating on it; it is clearly different from person to person and more a fiction which results from their expertimental setting in Aerrts and Gabora (2005) than an observable concept state.
Ontologies in information science are necessary to explain how a concept is used in an information system application. This application gives the context for the concepts. The ontology is appropriate if it formalizes the concepts as they are used in the application -- more should not be demanded.
A concept in one information system is in a different context than in another one. Understanding the relations between the same concept used in two different applications (i.e. in two different contexts) is difficult; this is the "interoperability problem". The metthods described by Aerts, Rosch and Gabora (2008) applying a quantum mechanical framework may be useful.
An ontology is right, if it describes the concept as it is used in the application; an ontology can only be judged in the context of the application. To construct ontologies outside of an application which fixes the context is not meaningful and judging an ontology without considering the context is inappropriate; it is not defined what would be a "good ontology" and what would be a "bad ontology" without a fixed context. -- I fear we are trying to often to much to produce an Ontology, describing reality, not our concepts of reality influenced by context.
Gabora, L.; Rosch, E. & Aerts, D. Toward an Ecological Theory of Concepts Ecological Psychology,, 2008, 20, 84-116
Aerts, D. & Gabora, L. A theory of concepts and their combinations I: The structure of the sets of contexts and properties Kybernetes, 2005, 34, 167-191
Aerts, D. & Gabora, L. A Theory of Concepts and Their Combinations II: A Hilbert Space Representation Kybernetes, 2005, 34, 0402205