- From: Pat Hayes <phayes@ihmc.us>
- Date: Mon, 17 May 2004 14:54:15 -0500
- To: Kendall Clark <kendall@monkeyfist.com>
- Cc: RDF Data Access Working Group <public-rdf-dawg@w3.org>
>On Tue, May 11, 2004 at 04:52:52PM -0700, Rob Shearer wrote: > >> 4.6 Additional semantic knowledge >> It should be possible for knowledge encoded in other semantic languages, >> such as RDFS, OWL, and SWRL to affect the results of queries about RDF >> graphs. > >In the interests of making progress, I'm willing to accept Rob's >version, above, of my original proposal. In the current UC&R doc, >my original is 4.6 and Rob's variant is 4.6a. > >So, I'd be willing to accept a modest reworking of 4.6a: > >Additional Semantic Information > >It should be possible for knowledged encode din other semantic >languages -- for example: RDFS, OWL, etc. -- to affect the results of >queries about RDF graphs. > >In fact, unless someone objects, I'd like to make that the language in >the document and the version which we vote on at some point. Sorry to rock the boat, but this requirement worries me. It is possible to interpret it as saying that a query-responder has a licence to use RDFS, OWL, etc., content to respond to any RDF query. I think that would be a very bad idea, if the query is unable to specify which of the various languages are intended to be used. Moreover, the term 'semantic language' is not defined, and according to some versions of what SWeb meaning boils down to, it could include unformatted English inside rdf:comment strings. Already we have a potential disagreement over whether SWRL counts as a semantic language. I would be happier if we did not have any such requirement. It seems to me to be orthogonal to the query language design, and a matter to be handled by an RDFS or OWL inference engine rather than by a querying protocol. Our charter explicitly says that the RDF graph being queried may be 'virtual' , so it could be an RDFS or OWL closure or the virtual graph obtainable from a given graph from a particular SWRL rule set: this provides us with a very neat way to avoid this issue and keep our attention focused on querying graphs rather than drawing inferences which may or may not be valid according to a variety of different semantic frameworks. Finally, the wording suggests that OWL and RDFS are 'other' than RDF, whereas in fact they are semantic extensions of RDF. At the very least, it ought to be possible to do a 'bare RDF' query, explicitly rejecting any reliance on any other non-RDF implication or machinery, and the requirement, if we keep it, should make this clear. Suggestion (if we must keep this requirement): Additional Semantic Information It should be possible for a query to indicate that the answers should take into account knowledge encoded in RDF semantic extensions, such as RDFS, OWL, etc.. Pat -- --------------------------------------------------------------------- IHMC (850)434 8903 or (650)494 3973 home 40 South Alcaniz St. (850)202 4416 office Pensacola (850)202 4440 fax FL 32501 (850)291 0667 cell phayes@ihmc.us http://www.ihmc.us/users/phayes
Received on Monday, 17 May 2004 15:54:18 UTC