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Re: The meaning of "representation"

From: Xiaoshu Wang <wangxiao@musc.edu>
Date: Tue, 04 Dec 2007 22:22:29 +0000
Message-ID: <4755D325.9010403@musc.edu>
To: Harry Halpin <hhalpin@ibiblio.org>
CC: noah_mendelsohn@us.ibm.com, Chimezie Ogbuji <chimezie@gmail.com>, Mikael Nilsson <mikael@nilsson.name>, Tim Berners-Lee <timbl@w3.org>, www-tag@w3.org



Harry Halpin wrote:
> Xiaoshu Wang wrote:
>   
>>> No.  Assuming binary coding is used, the message is a sequence of
>>> bits. It is presumed that the sender and receiver agree in advance on
>>> the range of possible information values (my term, not Shannon's),
>>> that a given message might convey;  each distinct message essentially
>>> selects one of those values.    From Shannon's 1948 paper [1]:
>>>   
>>>       
>> I take the 'no' means that the message is not embedded?
>>     
> Noah's right - there's a a big difference between Shannon's theory,
> about the reliability of transferring information via messages, and the
> common-sense use of the word "information" which denotes something with
> a meaning. Now what Tim means precisely, I'm not entirely sure of, but
> there clearly a distinction between me and my web-page. It may not be a
> rigid distinction, maybe more of a continuum, but there's likely a
> distinction. You might want to look into Dretske, who investigates the
> "semantic theory of information" (which does end up being subjective).
> See my notes [1] if interested.
>   
I didn't argue Noah's interpretation of Shannon's theory.  My viewpoint 
is the same as yours - "Shannon uses this theory to quantify /*how 
much/* information the message contains".  What I think, Noah is trying 
to argue, for Tim,  that information can be a concrete entity and to be 
directly modeled, because, my argument was that there is only something 
*act as* information but nothing *is* information.  But of course, as 
you said, we have different definition about "information".
>> I snip the rest (to shorten the message) because I agree your
>> interpretation of Shannon's theory. However, I disagree that the
>> assumption that the number of messages, with regard to a URI's
>> representations, is finite. In principle, I can use ONE bit message in
>> conjunction with various content types to answer all your questions
>> about the resource. From a communication point of view, a user do not
>> have a pre-established context with the resource.
>>     
> At a given time it would seem that the number of possible
> representations returned by a URI is finite. And the user does have a
> pre-established context with the resource, via the standards implemented
> by the browser, etc. etc. It may not completely determine the
> interpretation of the resource as regard a human user (although it might
> for a computer), but then....nothing does in any sort of communication
> when humans are involved.
>   
Well, now you used another term "representation".  Is "representation" 
information or a carrier of information? This is what is at debate.

Xiaoshu 
Received on Tuesday, 4 December 2007 22:24:09 GMT

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