- From: pat hayes <phayes@ai.uwf.edu>
- Date: Tue, 3 Apr 2001 09:42:09 -0700
- To: Sandro Hawke <sandro@w3.org>
- Cc: www-rdf-logic@w3.org
>Peter F. Patel-Schneider wrote: > > There has recently been a discussion on the semantic problems with RDF. > > > > I strongly agree with Pat Hayes's characterization of RDF (and RDFS) as > > based on a fundamentally flawed semantic model > >I agree there's a flaw here. I'm afraid it may be hard to really >address it while maintaining the desired quality of RDF as "universal" >and relatively independent of contentious design issues. I honestly don't think so. The basic ideas of logical inference have been around now for about 2000 years and they still hold good even on the Web. >I'm going to go out on a limb here and propose a solution that I think >provides solid semantics without being unduly restrictive. It's >simple: reduce the RDF model to binary relations stated with >locally-scoped terms which may be defined directly in English (not >indirectly as URIs attached to semantics by various standards bodies >and by application developers). Not sure I follow this, but English is not a good way to state semantic meanings! >More formally, in prolog syntax, the RDF model would be defined as >having two relations: > > binary_relation(subject_term, relation_term, value_term). > >which means that the relationship identified by the relation_term (by >the mechanism defined below) is truly held between some object >identified by the subject_term and some object identified by the >value_term, respectively. > >The definitional grounding for the relation_term and optionally for >the other terms would be provided by: > > english_definition(term, "This is English text which defines something"). > >This approach allows semantics to be defined with arbitrary precision >for humans by allowing the inclusion of entire textbooks or legals >codes if necessary. But it doesnt provide any model-theoretic semantics, since English doesnt have a model theory. The point is not to pin down the meaning for English readers, but to provide a mathematically checkable notion of valid inference for machines. >And it allows machine processing via the >crude-but-effective mechanism of exact matching of strings. The longer the prose gets, the harder it is to get exact string matching. > In >effect, English text strings become the unique-identifiers which >people are using in RDF today. I will agree that allowing a broader notion of unique-identifier might be handy. Pat Hayes --------------------------------------------------------------------- IHMC (850)434 8903 home 40 South Alcaniz St. (850)202 4416 office Pensacola, FL 32501 (850)202 4440 fax phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes
Received on Tuesday, 3 April 2001 13:55:00 UTC