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Re: Uniform access to descriptions

From: Xiaoshu Wang <wangxiao@musc.edu>
Date: Sat, 12 Apr 2008 14:12:53 +0100
Message-ID: <4800B554.4080604@musc.edu>
To: Tim Berners-Lee <timbl@w3.org>
CC: Pat Hayes <phayes@ihmc.us>, noah_mendelsohn@us.ibm.com, Jonathan Rees <jar@creativecommons.org>, Phil Archer <parcher@icra.org>, "Williams, Stuart (HP Labs, Bristol)" <skw@hp.com>, "www-tag@w3.org WG" <www-tag@w3.org>



Tim Berners-Lee wrote:
> Xiaoshu,
>
> On 2008-04 -12, at 05:37, Xiaoshu Wang wrote:
>> I think TAG's httpRange-14 is the following logic.
>>
>> Representation=Resource if HTTP=200.
>>
>
> The relation ship is not equality.   It is 'representation'.  The 
> resource is an abstract document.
> The thing returned, with a 200 response, is a tag:representation of 
> the document,
>
>
> Loosely, It is a representation using some form of languages and 
> encoding of the meaning of the document.   Some languages may be 
> better at giving ht meaning than others.  Also some languages can be 
> more easily assimilated by  a program than others.  But the 
> architecture of the web relies on the fact that if I find out some 
> information from a document with URI x, then I can quote x to someone 
> else and expect them to be able to get the same information.  Even if 
> they are using different hardware and software and have a different 
> screen size, and so on.   They might get degraded information through 
> conneg: for example, if they can only get RDF and there is information 
> on the HTML version which isn't encoded in the RDF version, then there 
> is loss, and the server should only do conneg if really the publisher 
> is quite happy with someone getting either conneged representation back.
>
> Conneg MUST NEVER be used to select between quite different documents, 
> or between a document and another document about the first document.
>
> That is the intent of the relation 'representation', as in 'the HTTP 
> 200 response is a representation of the document'.
>
> ('document' is called 'InformationResource' in the AWWW)
Isn't that give us (at least me) the problem?  First, I don't know what 
is a "document" and what is not.  Second, 200 then implies some kind of 
equivalence, (in your words that is not *quite different*), how do I 
judge what kind of difference is *quite* different and what is not 
*quite* different?

It is not I try to argue for the sake of argument, because that sort of 
wording doesn't help me dong anything in practice.

Xiaoshu
Received on Saturday, 12 April 2008 13:13:39 GMT

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