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RE: issue-dbooth-10: Does an XML namespace necessarily imply semantics?

From: Booth, David (HP Software - Boston) <dbooth@hp.com>
Date: Tue, 19 Jun 2007 18:40:18 -0400
Message-ID: <EBBD956B8A9002479B0C9CE9FE14A6C202CCA9A5@tayexc19.americas.cpqcorp.net>
To: "Harry Halpin" <hhalpin@ibiblio.org>
Cc: <public-grddl-comments@w3.org>

Yes, I am satisfied with this change.  It looks great.

Thanks

David Booth, Ph.D.
HP Software
+1 617 629 8881 office  |  dbooth@hp.com
http://www.hp.com/go/software

Opinions expressed herein are those of the author and do not represent
the official views of HP unless explicitly stated otherwise.
 

> -----Original Message-----
> From: Harry Halpin [mailto:hhalpin@ibiblio.org] 
> Sent: Tuesday, June 19, 2007 6:38 PM
> To: Harry Halpin
> Cc: Booth, David (HP Software - Boston); public-grddl-comments@w3.org
> Subject: Re: issue-dbooth-10: Does an XML namespace 
> necessarily imply semantics?
> 
> Note that I have added the following paragraph to the GRDDL Primer[1],
> which I believe satisfies your comment, David:
> 
> This sentence  is padding to make it flow with the rest of the primer:
> 
> "In this example, the link to the GRDDL transformation was added by
> hand. However, as shown in detail in the GRDDL specification [GRDDL]
> <http://www.w3.org/2001/sw/grddl-wg/doc29/primer.html#GRDDL>, a
> GRDDL-aware agent can also retrieve the namespace document of an XML
> dialect to find a GRDDL transformation by "following its 
> nose" from the
> namespace on the root element of the GRDDL source document to the
> namespace document. "
> 
> 
> This is the sentence that I believe addresses your comment:
> 
> "The use of a namespace on the root element represents a declaration
> that the document conforms to the authoritative definition of that
> namespace as defined by the namespace owner, which may include a
> transformation from that XML dialect into RDF using GRDDL."
> 
> Is your comment satisfied?
> 
> [1]http://www.w3.org/2001/sw/grddl-wg/doc29/primer.html
> 
> 
> Harry Halpin wrote:
> >
> > On Tue, 29 May 2007, Booth, David (HP Software - Boston) wrote:
> >
> >> This is not a significant issue from my perspective, since as DanC
> >> pointed out, the TAG has already answered the question.  (I was not
> >> aware that it had when I wrote the issue.)
> >>
> >> In looking over the GRDDL primer editor's draft:
> >> http://www.w3.org/2001/sw/grddl-wg/doc29/primer.html
> >> I don't see any example of using a 
> namespaceTransformation, and that is
> >> the place where it would have been natural to add an 
> explanation of the
> >> namespace semantics.  If the primer is expanded to include such an
> >> example, then I suggest added text along the lines of: "Use of a
> >> namespace on the root element represents a declaration 
> that the document
> >> conforms to the semantics of that namespace as defined by 
> the namespace
> >> owner" and reference the TAG's decision on this.
> >
> > Thanks David, if we use such an example in the Primer, we will add
> > that text.
> >
> >>
> >> In short, I'm fine with leaving this to the editors' 
> discretion, so this
> >> issue can be closed.  I am satisfied with the WG's response.
> >>
> >> Thanks
> >>
> >> David Booth, Ph.D.
> >> HP Software
> >> +1 617 629 8881 office  |  dbooth@hp.com
> >> http://www.hp.com/go/software
> >>
> >>
> >>> -----Original Message-----
> >>> From: Harry Halpin [mailto:hhalpin@ibiblio.org]
> >>> Sent: Friday, May 25, 2007 7:35 PM
> >>> To: Booth, David (HP Software - Boston)
> >>> Cc: public-grddl-comments@w3.org; Jeremy Carroll; McBride, Brian
> >>> Subject: RE: issue-dbooth-10: Does an XML namespace
> >>> necessarily imply semantics?
> >>>
> >>> I am happy to (about to go on 2 week vacation, but when I 
> return) add
> >>> warning text to primer if it is thought necessary. If so,
> >>> David, please
> >>> provide the exact text. Does this satisfy this comment?
> >>>
> >>> Furthermore, as regards the spec and GRDDL itself, it seems
> >>> to implicit in
> >>> the very  definition of GRDDL that by using a namespace document.
> >>>
> >>> "Likewise, by specifying a GRDDL namespace transformation 
> or profile
> >>> transformation, the creator of that namespace or profile
> >>> states that the
> >>> transformation will provide a faithful RDF rendition of a
> >>> class of source
> >>> documents which relate to that namespace or profile. A
> >>> namespace document
> >>> or a profile document also provide a means for their authors
> >>> to explain in
> >>> prose the purpose of the transformation or any policy 
> statements." [1]
> >>>
> >>> Providing a faithful rendition is another way of hitting upon
> >>> the same
> >>> issue regarding the use of an XML Vocabulary, as in the  case
> >>> of Ralph he
> >>> would not be providing a faithful rendition.
> >>>
> >>> Note that furthermore the TAG has made this decision re the
> >>> root node, not
> >>> all the nodes. Thus, this does support our decision to 
> postpone any
> >>> issues about applying GRDDL transformations to XPath nodes not
> >>> specified on on the root node.
> >>>
> >>> [1]http://www.w3.org/2004/01/rdxh/spec
> >>>
> >>> ware - Boston) wrote:
> >>>
> >>>>
> >>>> While I was preparing the message below, DanC replied to
> >>> Jeremy's query
> >>>> on this, saying that the WG and TAG had considered this
> >>> question, and an
> >>>> XML namespace on the root element *does* imply a certain set of
> >>>> semantics:
> >>>>
> >>> 
> http://lists.w3.org/Archives/Public/public-grddl-wg/2007May/0071.html
> >>>>
> >>>> FWIW, I agree with the TAG's position on this, so the 
> only remaining
> >>>> question for the GRDDL WG is whether the GRDDL spec 
> should include a
> >>>> warning about this.  Actually, I think the best approach 
> might be to
> >>>> include a brief explanation of this in the GRDDL primer.
> >>>>
> >>>> David Booth, Ph.D.
> >>>> HP Software
> >>>> +1 617 629 8881 office  |  dbooth@hp.com
> >>>> http://www.hp.com/go/software
> >>>>
> >>>>
> >>>>> -----Original Message-----
> >>>>> From: public-grddl-comments-request@w3.org
> >>>>> [mailto:public-grddl-comments-request@w3.org] On Behalf Of
> >>>>> Booth, David (HP Software - Boston)
> >>>>> Sent: Friday, May 25, 2007 11:50 AM
> >>>>> To: public-grddl-comments@w3.org
> >>>>> Cc: Jeremy Carroll; McBride, Brian
> >>>>> Subject: issue-dbooth-10: Does an XML namespace necessarily
> >>>>> imply semantics?
> >>>>>
> >>>>>
> >>>>> This is a personal comment -- not on behalf of HP.
> >>>>>
> >>>>> This is the formal submission of the comment Jeremy already
> >>>>> sent to the
> >>>>> WG on my behalf:
> >>>>>
> >>> 
> http://lists.w3.org/Archives/Public/public-grddl-wg/2007May/0061.html
> >>>>>
> >>>>> Does an XML namespace necessarily imply a certain set 
> of semantics?
> >>>>> Suppose Freddy at example.org defines a convenient XML 
> schema for
> >>>>> writing a person's legal residence ("a:primaryAddress") a
> >>>>> vacation home
> >>>>> address ("a:secondaryAddress"), such as:
> >>>>>
> >>>>> <a:root xmlns:a="http://example.org/AddressSchema.xml">
> >>>>>   <a:primaryAddress>25 Park St, Rochester, NY</a:primaryAddress>
> >>>>>   <a:secondaryAddress>88 Spring St, Salem, 
> MA</a:secondaryAddress>
> >>>>> </a:root>
> >>>>>
> >>>>> Freddy makes the XML schema definition downloadable from
> >>> the namespace
> >>>>> URI, and separately provides prose documentation to his users
> >>>>> explaining
> >>>>> the meaning and purpose of a:primaryAddress and
> >>> a:secondaryAddress in
> >>>>> his application.  In essence, Freddy's app treats this 
> document as
> >>>>> though it had made the following assertions:
> >>>>>
> >>>>>   foo:_lucy foo:legalResidence "25 Park St, Rochester, NY".
> >>>>>   foo:_lucy foo:vacationAddress "88 Spring St, Salem, MA".
> >>>>>
> >>>>> Later, Ralph needs a schema for billing and shipping
> >>> addresses and he
> >>>>> notices that Freddy's AddressSchema has the exact form he needs:
> >>>>> a:primaryAddress could represent the billing address and
> >>>>> a:secondaryAddress could represent the shipping 
> address.  In other
> >>>>> words, Ralph wishes to reuse the syntax only.  (This is
> >>> analogous to
> >>>>> implementation inheritance in OO programming.)  Raph notes
> >>> that an XML
> >>>>> schema only defines the structure of a document -- not the
> >>>>> semantics --
> >>>>> and the namespace spec does not seem to say anything about
> >>>>> the semantics
> >>>>> of a namespace either.  Ralph reuses Freddy's schema by
> >>> reference, and
> >>>>> provides separate prose documentation to his users
> >>> explaining that the
> >>>>> syntax (only) of Freddy's schema is being reused but the
> >>> semantics are
> >>>>> to be the semantics specified by Ralph.  Example:
> >>>>>
> >>>>> <a:root xmlns:a="http://example.org/AddressSchema.xml">
> >>>>>   <a:primaryAddress>123 Winter St, Palo Alto, 
> CA</a:primaryAddress>
> >>>>>   <a:secondaryAddress>444 El Camino, San Diego,
> >>>>> CA</a:secondaryAddress>
> >>>>> </a:root>
> >>>>>
> >>>>> In essence, Ralph's app treats this document as though it
> >>> had made the
> >>>>> following assertions:
> >>>>>
> >>>>>   fum:_desi fum:billingAddress "123 Winter St, Palo Alto, CA".
> >>>>>   fum:_desi fum:shippingAddress "444 El Camino, San Diego, CA".
> >>>>>
> >>>>> Later Freddy decides to update his XML schema document at
> >>>>> http://example.org/AddressSchema.xml to declare a GRDDL
> >>> transformation
> >>>>> in the namespace document such that the above example
> >>> would be GRDDL
> >>>>> transformed to RDF.  Ralph may have no knowledge of GRDDL
> >>> and may be
> >>>>> unaware of this change, but suddenly Ralph's documents gain the
> >>>>> semantics of Freddy's documents according to the GRDDL spec.
> >>>>> Questions
> >>>>> Was Ralph wrong to re-use Freddy's namespace and syntax
> >>> schema while
> >>>>> imparting his own semantics to that schema?  If so, what
> >>> spec forbids
> >>>>> this?  (Presumably this is a question for the W3C TAG.)
> >>>>>
> >>>>> My own view at present is that a namespace should be viewed
> >>>>> as implying
> >>>>> the semantics that its owner declares, regardless of
> >>> whether GRDDL is
> >>>>> used.  Hence, Ralph should not give his document different
> >>> semantics
> >>>>> than Freddy somehow specifies via his namespace document.
> >>> If Freddy's
> >>>>> semantics are not clear to Ralph, then Ralph should not
> >>> use Freddy's
> >>>>> namespace, due to the risk of guessing wrong.
> >>>>>
> >>>>> However, since I do not at present see anything in the
> >>>>> namespace spec or
> >>>>> the WebArch that forbids this kind of syntax-only reuse,
> >>> perhaps the
> >>>>> GRDDL spec should address the possibility of its allowance.
> >>>>> If so, what
> >>>>> should the GRDDL spec say?
> >>>>>
> >>>>> Option 1: Add some warning text in the spec.  This might include
> >>>>> suggesting that GRDDL aware agents check last modified times
> >>>>> on docs and
> >>>>> namespace docs, but this does not seem like it would be 
> reliable.
> >>>>>
> >>>>> Option 2: Record a postponed issue (possibly to be referred
> >>>>> to the TAG).
> >>>>>
> >>>>> At present I think either option would be okay.
> >>>>>
> >>>>>
> >>>>> David Booth, Ph.D.
> >>>>> HP Software
> >>>>> +1 617 629 8881 office  |  dbooth@hp.com
> >>>>> http://www.hp.com/go/software
> >>>>>
> >>>>>
> >>>>
> >>>>
> >>>
> >>> -- 
> >>>                  --harry
> >>>
> >>>      Harry Halpin
> >>>      Informatics, University of Edinburgh
> >>>          http://www.ibiblio.org/hhalpin
> >>>
> >>
> >
> 
> 
> -- 
> 		-harry
> 
> Harry Halpin,  University of Edinburgh 
> http://www.ibiblio.org/hhalpin 6B522426
> 
> 
Received on Tuesday, 19 June 2007 22:41:12 GMT

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