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RE: SKOS 'concept schemes' and DCMI 'vocabulary encoding schemes'

From: Pete Johnston <p.johnston@ukoln.ac.uk>
Date: Mon, 10 Oct 2005 17:40:55 +0100
To: "'Miles, AJ (Alistair)'" <A.J.Miles@rl.ac.uk>, DC-RDF-TASKFORCE@jiscmail.ac.uk
Cc: public-esw-thes@w3.org
Message-ID: <002e01c5cdb9$6292d140$2392268a@ulpcpj>


> Quoting from [1] section 2.3 ...
> 
> 'In the case where there is a URI, specifying the object we 
> want to use in it's relation with the scheme, we could make 
> an rdfs:isDefinedBy arc pointing to that URI. Such a triple 
> of RDF(S) properties hanging off a resource is what one may 
> call: Poor Man's Structured Values'

I'm still not sure "specifying the object we want to use in it's
relation with the scheme" says that the object of the rdfs:isDefinedBy
is the URI of the encoding scheme though. I'm not sure what it says,
really - English wasn't the writer's first language! But I think if
Roland had meant URI2 to be the URI of the scheme, he would have used
such a URI explicitly to make that point. And the example in the graph
in 2.3.2 seems to suggest otherwise. 

> Oh, another thought, the only way I can see 'Vocabulary 
> Encoding Scheme' mapping to RDF as is, without changing the 
> AM, is to model them as RDF datatypes.  I.e.:
> 
> <http://www.example.com/somedoc> dc:subject 
> 'D08.586.682.075.400'^^dcterms:MESH.
> 
> Although I certainly can't claim to understand the finer 
> points of how an RDF datatype maps a set of literal values to 
> resources, the notion of a datatype in RDF seems to fit best 
> with the notion of 'encoding' as it is described in the DCMI AM.
> 
> Would it be possible to allow both e.g. ...

[snip]

I dunno.... I'll have to think about that!

> Also, the pattern:
>
> <http://www.example.com/somedoc> dc:subject
'D08.586.682.075.400'^^dcterms:MESH.
>
> ... seems to also match closely the XML encoding of qualified DC,
using xsi:type.

Urgh... 

As I said in the DC Arch meeting 

http://www.ukoln.ac.uk/metadata/dcmi/dc-xml-issues/

that's a mess, and it doesn't even provide a binding for the DCAM. So
let's not argue from there! ;-)

I have some proposals for alternatives that I have to get out to dc-arch
for discussion, but I've been too busy with non-DC stuff since Madrid.
But, yes,  I'm inclined to agree that if the XML binding uses xsi:type
at all (which is debatable as it then ties the binding to W3C XML Schema
and not everyone likes that!), then it should use it for literal
dataypes/syntax encoding schemes only.

Pete
Received on Monday, 10 October 2005 16:39:49 GMT

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