- From: Libby Miller <Libby.Miller@bristol.ac.uk>
- Date: Mon, 9 Sep 2002 23:30:48 +0100 (BST)
- To: Jeff Heflin <heflin@cse.lehigh.edu>
- cc: WebOnt <www-webont-wg@w3.org>
Jeff, do we need owl-specific properties? Dan Brickley and I wrote a brief document about versioning metadata vocabularies, and I think the issues might hold here too: http://www.ilrt.bris.ac.uk/discovery/2001/06/process/ Libby On Mon, 9 Sep 2002, Jeff Heflin wrote: > > Here are my initial thoughts on the issue: > > We need various properties to handle elements of versioning with > ontologies. > > My proposed solution consists of adding three new features to owl. These > are for indicating prior versions, backward copatibility and > deprecation. > > > Prior versions: > ---------------- > <url> priorVersion <url>. > > The second URL is an earlier version of the first. This has no meaning > in the semantics, but could be used by software to organize ontologies > by versions. Due to XML namespaces the identifiers in the two ontologies > will be treated as distinct unless there are explicit statements of > equivalence. Thus, the two ontologies can be merged without problems, > although there will be no "integration" unless specific mappings are > defined. > > > Backward compatibility: > ------------------------ > <url> backCompatWith <url>. > > The first URL is a later version of the second, and is "semantically" > backward compatible with it. This is basically syntactic sugar with the > following effects: > > Assuming A backCompatWith B, then: > * A priorVersion B. > * all classes in B are the sameClassAs a class in A with the same ID. > * all properties in B are the samePropertyAs a property in A with the > same ID. > Note this depends on the resolution of the synonym issue (I prefer > sameAs for both classes and properties). > > The sameAs statements essentially allow you to integrate data that > commit to different (backward-compatible) versions of the same ontology. > > Note, that this approach does not address the problem described in > Section 3.2 of the Requirements Document (under RDF(S) Support). There, > we gave an example where we wanted to "fix" an incorrect definition of > Dolphin. Note, given the approach here, we cannot make the new version > of the ontology backward-compatible with the old one because that would > say that the class of Dolphins is both a sublcass of Fish and Mammal. I > am still working on a clean way to solve this problem that meshes with > the model theories we are working towards. We may have to save this for > a "next version" of OWL. > > > Deprecation: > ------------- > <url> deprecates <classId> > <url> deprecates <propertyId> > > This allows an ontology to deprecate a class or property. By deprecating > the term, it means it still is sameAs a term with the same ID in the new > ontology, but that the term should not be used in new ontologies. This > allows an ontology to maintain backward-compatibility while phasing out > old vocabulary. Deprecation should only be used in ontologies that are > backward-compatible. > > This has no effect on the semantics, but authoring tools should use it > in error checking OWL markup. > > Note that deprecation allows you to break the transitivity of the > backCompatWith relation. > > Jeff > > > References: > ------------ > - Dynamics Research Corporation. DRC VES (Versioning) Ontology. At: > http://orlando.drc.com/daml/Ontology/VES/3.2/drc-ves-ont.daml > > - Heflin, J. Towards the Semantic Web: Knowledge Representation in a > Dynamic, Distributed Environment. Ph.D. Thesis, University of Maryland, > College Park. 2001. At: > http://www.cse.lehigh.edu/~heflin/pubs/#heflin-thesis (Sect. 3.4) > > - Heflin, J. and Hendler, J. Dynamic Ontologies on the Web. In > Proceedings of the Seventeenth National Conference on Artificial > Intelligence (AAAI-2000). AAAI/MIT Press, Menlo Park, CA, 2000. pp. > 443-449. At: http://www.cse.lehigh.edu/~heflin/pubs/#aaai2000 > > - Klein, M. and Fensel, D. Ontology Versioning on the Semantic Web. In > First International Semantic Web Working Symposium (SWWS'01), 2001. At: > http://www.semanticweb.org/SWWS/program/full/paper56.pdf > > >
Received on Monday, 9 September 2002 18:33:00 UTC