- From: Ed Barkmeyer <edbark@nist.gov>
- Date: Thu, 02 Mar 2006 17:52:45 -0500
- To: Michael Kifer <kifer@cs.sunysb.edu>
- CC: RIF WG <public-rif-wg@w3.org>
Michael, Obviously we disagree. I leave it at that. One clarification. I wrote: >>But suppose that Rex needs >>to send this ruleset to Regina, so that Regina can use its local KB to assist >>Rex in making some inferences. Then when Rex sends the RIF ruleset to Regina, >>the SPARQL queries to Uhu that appear in some of the antecedents must have a >>RIF representation. (And I think this is in some sense the degenerate case. >>It is entirely possible that Regina is a 'hybrid' site, combining both DL and >>Rules reasoning capabilities, with the consequence that Regina wants to >>"understand" the SPARQL query, not just blindly send it to Uhu.) > > "Understand" the sparql query? Are you talking about meta-reasoning about > rule programs? You are dragging the whole thing into the direction of > impossible or, at least, of something that is well beyond the current > technologies. No. What I meant was: Since Regina-the-hybrid has some associate DL reasoner, and the SPARQL query presumably involves "terms" (URIs) and DL/RDF concepts that may be meaningful to Regina's associated DL reasoner, given the DL ontologies available to Regina, Regina may want to process the embedded SPARQL query thru Regina's DL side, with whatever consequences that has for Regina's KB. If the RIF model of the query is "send this XML string to Uhu with two 'macro' substitutions", Regina won't be able to tell SPARQL from JDBC, and can't profit locally from the results. I am willing to agree that this is "forward-looking", but frankly the whole idea of RIF having to interwork with OWL and RDF reasoners in any regard is "forward-looking". And it is not at all clear to me what kinds of swallows will first nest under that roof. > The exact form of RIF to OWL/RDF queries is yet to be determined, but I > doubt that they will be some kinds of translations from SPARQL or OWL to RIF. > More likely they will resemble current interfaces from rule languages to > databases. I would agree with this, and I certainly wouldn't expect more from phase 1, but it seems to me that when Francois Bry and I postulated this a month ago, we were 'roundly abused' by some other "forward-looking" members of the WG. It seems that no view of the future is widely held. And that's probably a good thing. ;-) -Ed -- Edward J. Barkmeyer Email: edbark@nist.gov National Institute of Standards & Technology Manufacturing Systems Integration Division 100 Bureau Drive, Stop 8263 Tel: +1 301-975-3528 Gaithersburg, MD 20899-8263 FAX: +1 301-975-4482 "The opinions expressed above do not reflect consensus of NIST, and have not been reviewed by any Government authority."
Received on Thursday, 2 March 2006 22:52:55 UTC