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Oops, just noticed that <rdf:Description rdf:about="http://testers.mkdoc.com:80/features/"> <dcq:references> <rdf:Bag> <rdf:li> <rdf:Description> <dcq:URI> <rdf:value>/features/accessibility/</rdf:value> </dcq:URI> <dc:title>accessible</dc:title> <dc:description>Information about MKDoc's accessibility features</dc:description> </rdf:Description> </rdf:li> ...etc doesn't parse as proper RDF anyway. (Or it shouldn't...) Regardless, using rdf:Bags for this sort of data is starting to look like overkill to me. Dan On Sat, 30 Jun 2001, Dan Brickley wrote: > On Sat, 30 Jun 2001, Dan Brickley wrote: > > > http://rdfweb.org/people/danbri/2001/06/dcarch-test/rdfq-tests.html > > > I've now added a third example, couched against a (tweaked) snapshot of > some more of the same data from Chris. > > > ...showing that we can pull together diverse metadata using RDF/DC. This > > example isn't too exciting since the three files are similarly formated > > and mention different resources. It would be more fun if the three files > > were linked using dc:relation qualifiers; maybe I'll have a go at that > > next time. Anyway, the live example seems to work in the (SiRPAC > > based) Java tool: it finds three resultset rows that match the query > > expression. > > I've just implemented this: > > http://rdfweb.org/people/danbri/2001/06/dcarch-test/rdfq-tests.html > > DCQ/RDF test 3: > > [[ > SELECT ?x, ?y, ?title1, ?title2, ?abstract1, ?abstract2, ?lastmod > FROM > http://rdfweb.org/people/danbri/2001/06/dcarch-test/relations/features_fix.rdf, > http://rdfweb.org/people/danbri/2001/06/dcarch-test/relations/humans_fix.rdf > WHERE > (dc::title ?x ?title1) > (dc::title ?y ?title2) > (dcq::abstract ?x ?abstract1) > (dcq::abstract ?y ?abstract2) > (dcq::references ?x ?y) > (dcq::modified ?y ?m) > (rdf::value ?m ?lastmod) > > USING dcq for http://dublincore.org/2000/03/13/dcq# > rdf for http://www.w3.org/1999/02/22-rdf-syntax-ns# > vcard for http://www.w3.org/2001/vcard-rdf/3.0# > dc for http://purl.org/dc/elements/1.1/ > ]] > > > The query runs, and finds a single result, providing URL and title for > each pair of pages linked by dcq:references, alongside the last-modified date > for the referenced page. This shows that the two chunks of RDF/DC data > have been successfully merged. > > To do this, I had to hack about with the data a bit: > > http://rdfweb.org/people/danbri/2001/06/dcarch-test/relations/features_fix.rdf > > Excerpt from tweaked version: > > <rdf:Description rdf:about="http://testers.mkdoc.com/features/"> > <dc:title>Features</dc:title> > <dcq:abstract> > MKDoc is a web site content management system that is very feature rich. > </dcq:abstract> > <dcq:references> > <rdf:Description rdf:about="http://testers.mkdoc.com/features/human-readable-web-addresses/"> > <dc:title>Human Readable Web Addresses</dc:title> > </rdf:Description> > </dcq:references> > > and tweaked humans.rdf file: > http://rdfweb.org/people/danbri/2001/06/dcarch-test/relations/humans_fix.rdf > > <rdf:Description rdf:about="http://testers.mkdoc.com/features/human-readable-web-addresses/"> > <dc:title>Human Readable Web Addresses</dc:title> > <dcq:abstract> > MKDoc has been designed to generate web sites that have human readable, > useable, and memorable addresses. > </dcq:abstract> > [...] > <dcq:modified> > <dcq:W3CDTF> > <rdf:value>2001-06-28T15:07:02Z</rdf:value> > <rdfs:label>Modified</rdfs:label> > </dcq:W3CDTF> > </dcq:modified> > > > > The interesting lesson from this is that the original structure of these > files (which to my best of my knowledge conforms to one reading of the > current DC/RDF draft) doesn't support such easy data merging. > > Instead, by using two layers of indirection, the relationship between > this pair of resources is a little obscured. The data's there and intact, > but RDF's "out of the box" data merging capability is (I'd argue) > neglected: > > The original structure was... (excuse the indenting...) > > <rdf:Description rdf:about="http://testers.mkdoc.com/features/"> > <dcq:references> > <rdf:Bag> > <rdf:li> > <rdf:Description> > <dcq:URI> > <rdf:value>/features/accessibility/</rdf:value> > </dcq:URI> > <dc:title>accessible</dc:title> > <dc:description>Information about MKDoc's accessibility > features</dc:description> > </rdf:Description> > </rdf:li> > </dcq:references> > > > The contrast is between: > > [page1] -- dcq:references --> [page2] (my tweaked version) > > and > > [page1] -- dcq:references --> [ bag_1 ] --- rdf:_1 --> [ ] --rdf:value-> [page2] > > (Chris's original data files). > > > On the basis of these experiments, I'm inclined to advise that the spec be > amended to discourage over-use of the RDF container constructs. I'm > actually tempted to claim that we should consider avoiding them > altogether, since the value of data-merging imho outweighs the information > supplied by employing the Bag/Seq/Alt machinery. But I want to make some > more test cases before making such a claim... > > Dan >