SCALABLE KNOWLEDGE COMPOSITION (original) (raw)
An abstract term is like a valise with a false bottom, you may put in what ideas you please, and take them out again, without being observed.
Alexis de Toqueville
Democracy in America, 1835.
The SKC project defines an ontology to be a set of terms and their relationships.
Terms refer to real-world and to abstract objects. Abstract objects are concepts which in turn can refer to sets of other abstract objects and real-world objects. The collections of real-world objects provides a grounding for the definitions, and an opportunity for validation of the meaning of the terms being employed.
The mapping of terms to objects will differ in various autonomous domains.
Relationships have semantic, and derived from that, structural significance. We may want to follow Sowa in keeping the number of relationship types constrained.
Multiple semantic relationship types may share structural relationship types, as IS-A, Ownership, Part-of, Reference, ... .
Again, the mapping of SKC relationship types to relationships employed in various ontologies will differ in various autonomous domains.
Instances of ontology types that the SKC algebra will have to consider include:
- object oriented class hierarchies,
- database schemas, often augmented with E-R or structural models
- semi-structured databases
- type specifications of enumerated sets
- definitional thesauri, as UMLS what is Cyc, ontolingua?
SKC specifically does not restrict its applicability to a purely extensional (object) or intensional (schema) definition of ontology, since its purpose is to support useful processing of extensions using intensional knowledge for all parties. To that end it is important that the intensional specification s include predicates or methods that permit the collection of extensional access to real-world objects.
We do not require ontologies to be complete specifications of a domain, but rather that usage of an ontology provide results complete with respect to the ontology.
comments are welcome, single iterations do not provide precision