W3C home > Mailing lists > Public > www-tag@w3.org > January 2003

Re: WebArch Ambiguity about Objects, PLUS Suggested Major Replacement

From: Graham Klyne <GK@NineByNine.org>
Date: Wed, 15 Jan 2003 16:13:23 +0000
Message-Id: <>
To: Sandro Hawke <sandro@w3.org>
Cc: www-tag@w3.org

At 10:31 AM 1/15/03 -0500, Sandro Hawke wrote:
> > At 12:32 PM 12/30/02 -0500, Sandro Hawke wrote:
> > >      Designers should be careful, however, to distinguish between
> > >      places where a web address is used to directly identify a web
> > >      page and those where it is used in this indirect manner to
> > >      identify something described on the web page.  (This is true
> > >      regardless of the use of fragment identifiers in web addresses;
> > >      they simply involve a portion of a web page.)
> > >
> > >I wonder how much of this statement the TAG agrees with.....   I
> > >wonder how the RDF community would feel about that last paragraph.
> >
> > I, for one, have no disagreement with this final paragraph.  But there's
> > something unsaid, which maybe doesn't need to be said in this context.  In
> > RDF, the referent of a URIref with fragment cannot be assumed to be a part
> > of the referent of the same URI without fragment identifier.  Any such
> > relationship, if it exists, needs to be stated separately.
> >
> > Suppose we have:
> >    someuri:Unicorn
> > and
> >    someuri:Unicorn#leftHindLeg
> > used in some RDF description.  Absent further information, we cannot 
> assume
> > that the second URIref denotes a part of the thing denoted by the first 
> URIref.
>I'd certainly agree that the notion of fragment-ness is in the domain
>of web architecture and none of RDF's business.  I like the idea of
>the RDF model theory treating identifiers as completely opaque.
>How do you explain to an web expert but newcomer-to-RDF what it means
>to put the string "http://www.w3.org/1999/02/22-rdf-syntax-ns#type" in
>the "Location" or "Address" field of their web browser?

It means to display the view identified by fragment identifier "type" 
within the document retrieved from 



If the document returned is text/html MIME type, that would be indicated by 
an anchor within the document.

If the document returned is application/xml MIME type, that would be an 
element within the document indicated by the value "type" on an attribute 
of type ID.

If the document returned is application/xml+rdf MIME type, that would be 
the RDF resource indicated by rdf:ID="type", or rdf:about="#type", or 
rdf:about="x", where x is any URI that when made absolute with respect to 
the base URI http://www.w3.org/1999/02/22-rdf-syntax-ns would yield the 
URIref "http://www.w3.org/1999/02/22-rdf-syntax-ns#type".


So if the document currently (as of 2003-01-15) obtained from 
http://www.w3.org/1999/02/22-rdf-syntax-ns were returned as 
application/xml+rdf, I would expect to see some rendering of the following 


   <Property ID="type"
     s:comment="Identifies the Class of a resource" />




Graham Klyne
Received on Wednesday, 15 January 2003 11:09:27 UTC

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