RE: Re: NOT SPAM: a request for information!
"Danny Ayers" <[email protected]>
| Newsgroups | gmane.comp.infodesign.facetedclassification |
|---|---|
| Message-ID | <[email protected]> |
Marvellous stuff! > Danny- I believe that representing facet restrictions using RDFS > simply involves specifying the range of the properties expressing > the facets. This hadn't occurred to me. Very neat indeed. > Unfortunately, one has to go to Full OWL to formally express that > tgm1:Term and tgm2:Term are disjoint classes, as in: > > <rdf:Description rdf:about="&tgm1:Term"> > <owl:disjointWith rdf:resource="&tgm2:Term"/> > </rdf:Description> This had occurred to me ;-) Although we're still taking baby steps with what can be done using the OWL layer [1] (the best example so far I guess is the Wine Agent [2]), I really think there's amazing potential. That the facetting can be expressed formally in such a concise fashion bodes well. (btw, I think OWL DL allows disjoint too) > But in practice, the use of URIs with lexically distinct namespaces > enforces the disjointness. So RDFS suffices to that extent. Right, perhaps in the category of cunning hack ;-) > Of course, this begs the question of how such restrictions are > enforced by the metadata respositories. But the representational > machinery is largely there in RDFS to express the restriction in > practice. Hmm - it's an interesting point, under what circumstances might it be desirable to enforce the restriction strictly. As you say (and demonstrate very nicely) the ability to use facets is there without the OWL mechanism. One to ponder... Cheers, Danny. ---- http://dannyayers.com [1] fyi, OWL is the Web Ontology Language, usually formulated as a layer on top of RDF which brings in a pile of relatively sophisticated, formally defined, description terms (such as owl:disjointWith). This allows vocabularies to be defined in more logically rigorous ways, hence allowing a lot more machine reasoning on them. http://www.w3.org/TR/2002/WD-owl-guide-20021104/ [2] http://onto.stanford.edu:8080/wino/index.jsp ------------------------ Yahoo! Groups Sponsor ---------------------~--> Get A Free Psychic Reading! Your Online Answer To Life's Important Questions. http://us.click.yahoo.com/Lj3uPC/Me7FAA/ySSFAA/0bmwlB/TM ---------------------------------------------------------------------~-> ---------- Thanks for playing. To unsubscribe from this group, send an email to: [email protected] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/