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Re: lcsh.info RDFa SKOS and content negotiation - use of RDF-style # IDs in RDFa?

From: Pat Hayes <phayes@ihmc.us>
Date: Tue, 30 Sep 2008 12:19:40 -0500
Cc: "Dan Brickley" <danbri@danbri.org>, RDFa <public-rdf-in-xhtml-tf@w3.org>, "www-tag@w3.org WG" <www-tag@w3.org>, "Ed Summers" <ehs@pobox.com>
Message-Id: <9BEDB29F-D287-4158-AF9C-1078C5E84FAE@ihmc.us>
To: "Steven Pemberton" <steven.pemberton@cwi.nl>


On Sep 30, 2008, at 6:30 AM, Steven Pemberton wrote:

>
> My preferred practice for naming concepts is to use blank nodes and  
> then foaf:primaryTopicOf to ground them:
>
> 	<link about="_:StevenPemberton" rel="foaf:primaryTopicOf" href="http://www.cwi.nl/~steven/ 
> " />
> 	<link about="_:Amsterdam" rel="foaf:primaryTopicOf" href="http://www.amsterdam.nl/ 
> " />
> 	<link about="_:W3C" rel="foaf:primaryTopicOf" href="http://www.w3.org/ 
> " />
> 	<link about="_:TheWasteLand" rel="foaf:primaryTopicOf" href="http://en.wikipedia.org/wiki/The_Waste_Land 
> " />
> 	<link about="_:Love" rel="foaf:primaryTopicOf" href="http://en.wikipedia.org/wiki/Love 
> " />
>
> <span about="_:TheWasteLand" property="dc:creator">T.S. Eliot</span>
> <a about"_:W3C" rel="foaf:homepage" href="http://www.w3.org/">W3C</a>

Using 'meaningful' labels for blank nodes is kind of cheating, though.  
These labels aren't part of the RDF graph itself, so could be  
eliminated on transmission. If you were to use _:1, _:2, etc., would  
your practice be as attractive?

Pat

>
>
> I have a nascent proposal to reserve a http scheme to make this  
> easier to write:
>
> 	<span about="pto:http://en.wikipedia.org/wiki/The_Waste_Land"  
> property="dc:creator">T.S. Eliot</span>
>
> but let's not argue about that now.

That looks nice.


>
>
> Best wishes,
>
> Steven
>
> On Tue, 30 Sep 2008 12:50:02 +0200, Dan Brickley <danbri@danbri.org>  
> wrote:
>
>> Looks like http-range-14 still haunts us. I'm looking for some best  
>> practice advice for using "#blahblah" URI IDs in RDFa content...
>>
>> Backstory -
>>
>> Edd Summers has put up a great site at http://lcsh.info/
>>
>> It has one page for each concept listed in the Library of Congress  
>> Subject Headings, eg. http://lcsh.info/sh85112589 is a URI for a  
>> document about the LCSH heading "Religion and the Humanities".
>>
>> There is RDFa in the HTML page, as well as a complete NTriples zip- 
>> file download of the dataset. The RDFa uses a #concept URI to  
>> identify the abstract concept that the document is describing with  
>> SKOS.
>>
>> <div class="concept" about="http://lcsh.info/sh85112589#concept"  
>> typeof="skos:Concept">
>>
>> The document also has an RDF/XML representation available by  
>> content negotiation. While the triples differ a little (Ed - is  
>> this a bug?), they all talk about the SKOS concepts via identifiers  
>> that take the main page's URI and append '#concept'.
>>
>> Is it TAG-acceptable to use a URI in this manner, when http://lcsh.info/sh85112589 
>>  is the URI for a document available in RDFa XHTML rather than RDF/ 
>> XML? What does "http://lcsh.info/sh85112589#concept" name? How do  
>> we 'follow our nose' here? Should the media type definition for  
>> RDFa allow the assignation of URIs to things other than chunks of  
>> markup?
>>
>> Does anyone have a suggestion for how if at all this should be done  
>> differently? My sense is that the HTML spec as-is doesn't license  
>> us to assign URIs in this way. And since #foo is to be interpreted  
>> w.r.t. to the (set of?) media types we get back as HTTP  
>> representations, there seems to be a tension here between using  
>> conneg and using rdfa and avoiding having to do http 303 redirects...
>>
>> cheers,
>>
>> Dan
>>
>>
>>
>> curl -s http://lcsh.info/sh85112589 | rapper -i rdfa - file:
>>
>> rapper: Parsing file <stdin> with parser rdfa and base URI file:
>> rapper: Serializing with serializer ntriples and base URI file:
>>
>> <file:> <http://www.w3.org/1999/xhtml/vocab#alternate> <http://lcsh.info/sh85112589.rdf 
>> > .
>> <file:> <http://www.w3.org/1999/xhtml/vocab#alternate> <http://lcsh.info/sh85112589.n3 
>> > .
>> <file:> <http://www.w3.org/1999/xhtml/vocab#alternate> <http://lcsh.info/sh85112589.json 
>> > .
>> <http://lcsh.info/sh85112589#concept> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type 
>> > <http://www.w3.org/2004/02/skos/core#Concept> .
>> <http://lcsh.info/sh85112589#concept> <http://www.w3.org/2004/02/skos/core#prefLabel 
>> > "Religion and the humanities" .
>> <http://lcsh.info/sh85112589#concept> <http://www.w3.org/2004/02/skos/core#altLabel 
>> > "Humanities and religion" .
>> <http://lcsh.info/sh85112589#concept> <http://purl.org/dc/terms/created 
>> > "1986-02-11" .
>> <http://lcsh.info/sh85112589#concept> <http://purl.org/dc/terms/modified 
>> > "1986-02-11T00:00:00" .
>> rapper: Parsing returned 8 triples
>>
>>
>> curl -H "Accept: application/rdf+xml" -s http://lcsh.info/ 
>> sh85112589 | rapper -i rdfxml - file:
>>
>> rapper: Parsing file <stdin> with parser rdfxml and base URI file:
>> rapper: Serializing with serializer ntriples and base URI file:
>>
>> <http://lcsh.info/sh85112589#concept> <http://www.w3.org/2004/02/skos/core#altLabel 
>> > "Humanities and religion"@en .
>> <http://lcsh.info/sh85112589#concept> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type 
>> > <http://www.w3.org/2004/02/skos/core#Concept> .
>> <http://lcsh.info/sh85112589#concept> <http://purl.org/dc/terms/created 
>> > "1986-02-11"^^<http://www.w3.org/2001/XMLSchema#date> .
>> <http://lcsh.info/sh85112589#concept> <http://www.w3.org/2004/02/skos/core#prefLabel 
>> > "Religion and the humanities"@en .
>> <http://lcsh.info/sh85112589#concept> <http://www.w3.org/2004/02/skos/core#broader 
>> > <http://lcsh.info/sh85062913#concept> .
>> <http://lcsh.info/sh85112589#concept> <http://purl.org/dc/terms/modified 
>> > "1986-02-11T00:00:00"^^<http://www.w3.org/2001/ 
>> XMLSchema#dateTime> .
>> <http://lcsh.info/sh85112589#concept> <http://www.w3.org/2004/02/skos/core#inScheme 
>> > <http://lcsh.info/> .
>> rapper: Parsing returned 7 triples
>>
>>
>>
>
>
>
>
>

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Received on Tuesday, 30 September 2008 17:20:27 GMT

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