By Andrew U. Frank, from the Research Group Geoinformation at the Technical University of Vienna
Abstract
I have suggested a treatment of ontology by tiers which capture different kinds of 'existence' (Frank 2001; Frank 2003). Separating the material existence in a continuous concept of the material world from the physical objects we form to reduce the complexity of reality has helped us to trace the origin of errors and uncertainty in our data.
In the presentation I will focus on the conceptual organization of the physical objects around us in classes and show how distinctions between objects construct taxonomies. Distinctions capture differences in qualities of objects which are important for understanding a situation or planning next actions. These distinctions are reflected in the classification of objects and indicate the operations an object affords.
In the talk I will present an approach to taxonomy which starts with a set of distinctions. This is different from many approaches which produce taxonomy of natural language terms. A taxon is characterized by the values for the distinction the objects classified have. A four valued logic (Belnap) is used and an order relation between taxa follows. A taxonomic lattice is constructed, in which for any two taxa a supertaxon and a subtaxon exist. It can be extended to include a taxonomy of relations and actions. Taxonomies constructed for different applications can be merged by simply merging the distinctions. Part_of relations between taxa result in dependencies between the distinctions.
I see four advantages in the use of distinctions to construct a taxonomic lattice:
- The focus on distinctions to define a taxonomy gives a calculus for taxa which does not require complex logic inferences.
- The taxonomy is finer than the lexicon of a natural language.
- The semantics of the taxa is grounded in the distinctions, which relate to observable qualities of the objects.
- The same approach (and the same distinctions) is used to classify objects, actions and relations.
References:
Frank, A. U. (2001). "Tiers of Ontology and Consistency Constraints in Geographic Information Systems." International Journal of Geographical Information Science 75(5 (Special Issue on Ontology of Geographic Information)): 667-678.
Frank, A. U. (2003). Ontology for Spatio-Temporal Databases. Spatiotemporal Databases: The Chorochronos Approach. M. Koubarakis, T. Sellis and e. al. Berlin, Springer-Verlag: 9-78.