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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


or in browsable form


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


or in browsable form


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



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

> 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 UTC

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