Towards RDFS 3.0 (or OWL 2 R Full)
Summary — there is a new “profile” of OWL Full that might be of great interest to the RDF/Data Web community — read on:
To those who follow W3C happenings, you know that I’ve had some problems with, and resigned from, the new OWL Working Group. The problems have mainly been related to the philosophy of what this is all about, more than the details of specific language features, and maybe I’ll blog about that some other time. However, in this entry I want to say something positive about one small piece of what the working group has done, and direct the RDF community to take a look at it– I believe it may be close to something we’ve needed for a long time.
In the “OWL 2 Web Ontology Language: Profiles” document (http://www.w3.org/TR/2008/WD-owl2-profiles-20080411/) the group has created a new set of OWL profiles (formerly called fragments) so instead of OWL Lite, DL, and Full, we now have (probably to be renamed at a later date) OWL 2 Full and a number of profiles OWL 2 DL, OWL 2 EL++, OWL 2 DL-Lite, OWL 2 R DL, and OWL 2 R Full (there are also be the unnamed RDF equivalents of the EL++ and OWL DL-Lite, but the group refuses to acknolwedge that, a primary reason for my leaving — but that’s another story again).
Anyway, it is to the last of these “OWL 2 R Full” that I would like to direct the attention of the RDF community — it is a bit hard to tell from the relatively cryptic document, but this fragment is an extension to RDFS that adds a small amount of useful OWL vocabulary, without requiring commitment to some of the strong restrictions needed for the various DL dialects. The specification includes an axiomatic specification of the language (i.e. rules) and starting to circulate, but not in the OWL group’s document, is an N3 version of the language making it very easy to see the relation to RDF. A couple of the larger members of the Working Group have stated that they will support this language (I’m not sure whether in public or not, so I’ll let them speak for themselves) which bodes well.
For those people looking at the “Data Web” or at “Web 3.0″ applications, I think this profile of OWL may be worth looking at — it would definitely be improved by some comments from serious Web 3.0 application developers – as it may well be a good target of opportunity for further RDF development. In the famous Semantic Web layercake, this profile (which I would like to see renamed RDFS 3.0) would be able to sit under the Rules and Ontology fragments, where RDFS is now, without derailing RDF(S) into the peculiarities of description logics, yet allowing some useful constructs to be added. For example, FOAF, DOAP and other of the most used RDF-based ontologies would be within (or close to) this new profile
So if you’re not interested, or are studiously ignoring, the OWL drafts, let me suggest you take a look at Table 2 of section 4 of the Profiles document (and section 4.2.3 if you want to see the rules). I also suggest that one does not have to understand anything else in that section (much of which seems to me to be written for those with PhDs in AI or similar background) to be able to see there’s something useful in here.
So take a look at OWL 2 R Full – the name is awful, but the language might be a really powerful new tool on the RDF Web.
-Jim Hendler
p.s. Let me also suggest taking a look at the public email by Michael Schneider at http://lists.w3.org/Archives/Public/public-owl-wg/2008Apr/0171.html – one of the few RDF proponents in the working group, he gives a great example of using OWL R Full in an RDFS context…