- From: Ivan Herman <ivan@w3.org>
- Date: Fri, 15 Jan 2010 10:08:05 +0100
- To: Gregory Williams <greg@evilfunhouse.com>
- CC: W3C SPARQL Working Group <public-rdf-dawg@w3.org>
- Message-ID: <4B503075.5080101@w3.org>
HI Greg, I am a little bit bothered by the usage of the rdfs:member property in[1]. It is, syntactically, correct, of course. However, the intention of rdfs:member was more 'operational' for RDFS reasoning than real usage: [[[ 5.1.6 rdfs:member rdfs:member is an instance of rdf:Property that is a super-property of all the container membership properties i.e. each container membership property has an rdfs:subPropertyOf relationship to the property rdfs:member. ]]] http://www.w3.org/TR/rdf-schema/#ch_member ie, it is some sort of a helper property for containers. I think that, from a modeling point of view, using lists would be cleaner. But then again, we run into our own problems of having difficulties querying lists...:-( Sigh. I am not sure whether we should change that, but I though that airing my (slight) discomfort is worthwhile... Ivan [1] http://kasei.us/2009/09/sparql/sd-example.ttl On 2010-1-15 04:33 , Gregory Williams wrote: > The last big piece of the service description vocabulary is the modeling of the "available universe" of graphs (using the sd:availableGraphDescriptions term). We had sketched this out at a very high level at the F2F2[1], but the exact modeling was never nailed down. > > Briefly, I see two open issues: what is the rdf:type of the "available universe" node and what is the property that connects this node with the available named graphs. The rdf:type might be something like sd:GraphCollection (being a collection of named graphs, but without a default graph it isn't a sd:Dataset). It's tempting to think that the property should be sd:namedGraph, already used in describing the default dataset, but then the domain of sd:namedGraph can't remain sd:Dataset. The GraphCollection essentially seems like an rdf:Bag, suggesting that the property might be a subproperty of rdfs:member. > > I'd also like to consider renaming the sd:graph property to sd:graphDescription to be more descriptive and to avoid confusion with the introduction of a sd:Graph class. > > I've sketched out what I think a full service description document might look like at [2] and welcome any feedback on these issues. > > thanks, > .greg > > [1] http://thefigtrees.net/lee/dl/sparql-IMG00009-20091103-1508.jpg > [2] http://kasei.us/2009/09/sparql/sd-example.ttl > > -- Ivan Herman, W3C Semantic Web Activity Lead Home: http://www.w3.org/People/Ivan/ mobile: +31-641044153 PGP Key: http://www.ivan-herman.net/pgpkey.html FOAF : http://www.ivan-herman.net/foaf.rdf vCard : http://www.ivan-herman.net/HermanIvan.vcf
Attachments
- application/pkcs7-signature attachment: S/MIME Cryptographic Signature
Received on Friday, 15 January 2010 09:07:16 UTC