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Re: ISSUE-57: The use of HTTP Redirection

From: Pat Hayes <phayes@ihmc.us>
Date: Thu, 30 Aug 2007 18:16:25 -0500
Message-Id: <p06230924c2fcfe392f0e@[10.100.0.16]>
To: Ed Davies <edavies@nildram.co.uk>
Cc: Technical Architecture Group WG <www-tag@w3.org>

>Richard Cyganiak wrote:
>>2. This boils down to a question wether to provide a representation 
>>of a resource, or instead provide an associated description of the 
>>resource (by means of a 303 redirect or hash truncation). What is 
>>the  difference between a representation and a description?
>
>A representation _is_ the thing (to some not quite fully
>defined level of approximation)

I really hope you are wrong about this. If you aren't, then 
everything written about the nature of representation for the past, 
say, 100 years, has been mistaken. One of the most basic assumptions 
of just about everyone who has written anything on semiotics or 
semantics is that the representation of something is distinct from 
the thing represented. Korzybski summed it up in a famous maxim of 
'general semantics': "the map is not the territory".

>whereas a description is
>only _about_ the thing.

And a representation is _of_ the thing.

>A huge file giving the exact position and state of every
>particle in a car (in a universe without quantum uncertainty)
>still wouldn't _be_ the car whereas a representation of a
>web page with all the styling markup removed would still
>be, to some extent, that web page.

You are mixing up representation with version. Two copies of a novel 
are, in a sense, the same novel. But they are different versions, or 
volumes if you prefer. The technical terminology used throughout 
linguistics for this is the type/token distinction. IN your example, 
the two differently styled versions of the same page would be 
different tokens of a common type. But none of this has anything to 
do with what is conventionally meant by a 'representation' of 
something.

The REST theory uses 'representation' in a special, highly 
restricted, way: but even so, it is careful to distinguish the 
resource itself (eg a web page) from its various representations 
(what you get sent when you do a GET on that page's URI)

Pat Hayes



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Received on Thursday, 30 August 2007 23:16:39 GMT

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