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Re: ANNOUNCE - SchemaWeb

From: Patrick Stickler <patrick.stickler@nokia.com>
Date: Thu, 20 Nov 2003 13:37:44 +0200
Cc: www-rdf-interest@w3.org
To: "ext Pete Johnston" <p.johnston@ukoln.ac.uk>
Message-Id: <F4F3C1B5-1B4D-11D8-8364-000A95EAFCEA@nokia.com>


Thanks, Pete, for touching on this issue. I had held back, figuring
folks were tired of that particular "soap box" of mine ;-)

For those interested in modelling vocabularies in RDF, have a look at

http://sw.nokia.com/schemas/general/VOC-1.0.rdf

or in browsable form

http://sw.nokia.com/uriqa?uri=http://sw.nokia.com/VOC-1&format=text/html

and to see how VOC supports the hierarchical organization of 
vocabularies
and subvocabularies with terms selected from arbitrary namespaces, have 
a
look at

http://sw.nokia.com/schemas/nokia/FN-1.0.rdf

or in browsable form

http://sw.nokia.com/uriqa?uri=http://sw.nokia.com/FN-1&format=text/html

I guess the VOC schema would be a candidate for SchemaWeb...  ;-)

Cheers,

Patrick



On Wednesday, Nov 19, 2003, at 16:29 Europe/Helsinki, ext Pete Johnston 
wrote:

>
> Victor Lindesay said:
>
>> SchemaWeb is at:
>> http://www.schemaweb.info/
>> Your feedback is welcome.
>
> Thanks for this. It is very nice indeed, and a very useful service.
>
> Apologies if this seems like nit-picking, but I have one query in that
> the display of metadata about a schema displays an entry "namespace",
> and I'm not quite clear what "namespace" means in this context. Is it
> the XML Namespace Name typically used in RDF/XML? Or is it used as a
> synonym for "vocabulary"?
>
> Anyway the data available suggests to me that there is a one-to-one
> correspondence between a schema and a "namespace".
>
> Patrick Stickler argued long and hard (and to me, at least,
> convincingly) on this list, see e.g.
>
> http://lists.w3.org/Archives/Public/www-rdf-interest/2002Jun/0016.html
>
> and elsewhere that namespaces-as-XML-Namespaces are simply part of the
> "punctuation" of the RDF/XML serialisation of RDF, and that there is no
> necessary one-to-one correspondence between:
>
> - what the RDF specs call a vocabulary (a set of URIrefs) (I think 
> there
> was an RDF Core decision to use the term "vocabulary" rather than
> "namespace" for this purpose precisely in order to avoid any confusion
> with XML Namespaces),
> - a schema (an RDF/XML document providing info about the resources
> denoted by those URIrefs), and
> - an XML Namespace.
>
> It _may_ be that for all my classes and properties with URIrefs
> beginning http://example.org/ns/, I create RDFS descriptions in one
> RDF/XML document which I make available at that URL, but there is no
> _requirement_ that that is the case.
>
> In fact one of the examples indexed by the registry highlights this. 
> The
> metadata for the schema for the RDFS vocabulary
>
> http://www.schemaweb.info/schema/SchemaDetails.aspx?id=2
>
> says
>
> Namespace: http://www.w3.org/2000/01/rdf-schema#
>
> But if you click on "classes and properties", you see that the data
> provided in the schema currently located at
>
> http://www.w3.org/TR/rdf-schema/rdfs-namespace.xml
>
> does (quite reasonably) include descriptions of resources such as
> http://www.w3.org/1999/02/22-rdf-syntax-ns#type etc - terms "from
> another namespace", if you like, which of course are also described by
> the schema located at
>
> http://www.w3.org/1999/02/22-rdf-syntax-ns
>
> and described by
>
> http://www.schemaweb.info/schema/SchemaDetails.aspx?id=1
>
> So I think I'm wondering whether describing a relationship between a
> schema and an XML Namespace is perhaps inappropriate; and while the
> relationship between schema and vocabulary (if that is what is intended
> by "Namespace" in this case rather than XML Namespace) may be worth
> describing, it is potentially many to many, as this example suggests?
>
> Cheers
>
> Pete
>
Received on Thursday, 20 November 2003 06:42:39 GMT

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