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Re: Subgroup to handle semantics of HTTP etc?

From: <noah_mendelsohn@us.ibm.com>
Date: Mon, 22 Oct 2007 10:16:20 -0400
To: wangxiao@musc.edu
Cc: Alan Ruttenberg <alanruttenberg@gmail.com>, Dan Connolly <connolly@w3.org>, "Booth, David (HP Software - Boston)" <dbooth@hp.com>, Jonathan A Rees <jar@mumble.net>, "Williams, Stuart (HP Labs, Bristol)" <skw@hp.com>, Tim Berners-Lee <timbl@w3.org>, W3C-TAG Group WG <www-tag@w3.org>
Message-ID: <OFE5B8FF80.9143B649-ON8525737C.004DD20A-8525737C.004E4293@lotus.com>

Xiaoshu Wang writes:

> Hmm.. not really.  I think AWWW's opinion is that for some resource,
> i.e., the information resource, T=R.

If that were the case, then why would we allow content negotiation based 
on media-type, language (French, English, Chinese, etc.)?  Furthermore, I 
think it's pretty well accepted that a 200 is an acceptable status code 
for a GET to a clock resource.  With such a resource we can see that the 
same URI (http://example.com/clock)  returns different representations 
each time it's accessed.   I find that a useful example to motivate the 
distinction between an information resource and its representation(s).

Furthermore, to reiterate the point about content negotiation, I think it 
would be quite acceptable for that clock to return a string like "10:03 AM 
EDT October 23, 2007" if asked for text/plain, but to return the image of 
a suitable clock face if asked for image/jpeg.  All of these illustrate 
the lack of one-to-one relationship between an information resource and 
its representations, at least in the general case.

Noah

--------------------------------------
Noah Mendelsohn 
IBM Corporation
One Rogers Street
Cambridge, MA 02142
1-617-693-4036
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Received on Monday, 22 October 2007 14:15:03 UTC

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