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RE: Significant W3C Confusion over Namespace Meaning and Policy

From: Jonathan Borden <jonathan@openhealth.org>
Date: Thu, 17 Feb 2005 13:50:59 -0500
Message-Id: <200502171851.j1HIp1BB056003@ohcg.spinweb.net>
To: "'Patrick Stickler'" <patrick.stickler@nokia.com>
Cc: <www-tag@w3.org>

Patrick Stickler

> Rather RDDL, or rather, the idea of namespace documents, 
> should just be dropped. Getting back a namespace document which 
> identifies all of the versions of all of the vocabularies, 
> schemas, ontologies, etc. employing terms from that namespace 
> is useless.

I understand, but of course do not agree with, your first sentence. I cannot
parse the rest of what you write.

> How is an application to know *which* version of *which* model to apply 
> in order to interpret the term in question? It can't, because a 
> given namespace is not tied to a specific version of a specific model 
> -- insofar as the specifications are concerned (and that's the key
point!). 

Err, wouldn't that be up to the author of the specification?

The arguments that I think I am hearing from you (again, I have difficulty
understanding most of what you are writing) seem as though you are arguing
both orthogonally and abstractly to what I understand is the issue being
raised in this thread. Let me summarize what I understand is the main
question here:

Suppose the W3C (i.e. a particular WG) authors a specification i.e. Version
1.0 of a particular REC. Later the W3C decides to revise the spec, e.g.
emits Version 2.0.

Also suppose that the REC is associated with a particular NS.

The issue is: if Version 2.0 alters the syntax and/or vocabulary of the REC,
i.e. introduces new terms and makes others, to use the English meaning of,
'redundant', ought the revised syntax use the same namespace URI or a new
one?

A specific example is RDF Version 1.0 vs. 2.0.

It seems that the confusion is that while it is stated that one ought not
use the same namespace URI when a vocabulary changes, that *in practice*
(e.g. RDF) the vocabulary changes while the NS remains the same.

-----

Now I see the utility of obtaining an OWL document when dereferencing a
namespace URI when in, for example, an RDF application, for example to
obtain an ontology defining an RDF property.

In the same way an XML Schema might be obtained when dereferencing a
namespace qualitifed XML element name, and this might be used to validate
the content.

What we were trying to do with RDDL (aside of course from providing human
readability) was to develop a way to obtain any of (for example): an OWL
ontology, an XML Schema, a RELAXNG schema or a DTD, so that software which
understands each of the above specs would each be able to get what it needs
out of a namespace URI. RDDL was designed so that, if the vocabulary author
wished, XML documents would not ***necessarily*** be tied to an ontology
written in a specific ontology definition language, or a schema written in a
specific schema definition language etc.

FWIW

Jonathan
Received on Thursday, 17 February 2005 18:51:09 GMT

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