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Re: Subgroup to handle semantics of HTTP etc?

From: Xiaoshu Wang <wangxiao@musc.edu>
Date: Tue, 23 Oct 2007 16:05:37 +0100
Message-ID: <471E0DC1.1040000@musc.edu>
To: "Williams, Stuart (HP Labs, Bristol)" <skw@hp.com>
CC: "Booth, David (HP Software - Boston)" <dbooth@hp.com>, W3C-TAG Group WG <www-tag@w3.org>, Alan Ruttenberg <alanruttenberg@gmail.com>, Jonathan A Rees <jar@mumble.net>, Dan Connolly <connolly@w3.org>, Tim Berners-Lee <timbl@w3.org>

Williams, Stuart (HP Labs, Bristol) wrote:
>> -----Original Message-----
>> From: Xiaoshu Wang [mailto:wangxiao@musc.edu] 
>> Sent: 23 October 2007 11:46
>> To: Williams, Stuart (HP Labs, Bristol)
>> Subject: Re: Subgroup to handle semantics of HTTP etc?
>>
>> Williams, Stuart (HP Labs, Bristol) wrote:
>>     
>>>> A representation is bound with its master URI, so we cannot talk 
>>>> about it without its master URI.
>>>>     
>>>>         
>>> Hmmm... I think you are still in a tangle trying to think of 
>>> representations as resources.
>>>   
>>>       
>> I am actually thinking otherwise. 
>>     
>>> Once you have lumpped all possible representations into a single
>>>       
> set, 
>   
>>> I don't see what distinguishing feature they have that enables you
>>>       
> to 
>   
>>> bind them to a b-node - it's just representation soup.
>>>   
>>>       
>> Representation is a-provoked resource in the sense that if 
>> there is no request, there is no representation.  If I define 
>> a class to represent representation, there is a necessary 
>> property relates it to a request.  
>> But an ordinary resource does not need this property to be a 
>> resource.  
>> Its existence does not depend on if there is a request.
>>     
>
> Well... I observe that you persist in wanting to speak of
> representations as resources.
>   
Well, I am a bit confused.  In the eye of semantic web, isn't everything 
in the world an rdf:Resource?  Isn't representation part of this world 
too? 
> Well is suppose that you can conceive of an inverse... and depending on
> whether you regard a representation as a particular message (in which
> case it arises because of an access attempt using a URI) or as a type
> for all messages that carry the specific sequence of bits/bytes... may
> or may not be functional, respectively.
>   
We don't differ here.
>> httpRange-14 trying to force the issue.  
>>     
>
> No... at the most, the TAG's httpRange-14 resolution:
>
> a) seeks to avoid ambiguity of reference between a thing and a
> description/depiction of a 
> thing.
>   
That is where the problem is.  A URI denotes a thing but *never* the 
description of that thing.  The *representation* returned by the server 
is a description of that thing.
 
When people think that "http://www.ihmc.us/users/phayes/PatHayes" should 
NOT denote Pat Hayes because they have confused the returned 
*representation* as the *resource* denoted by that URI.
> b) leave the range of what can be referenced by an http: URI sans
> fragment, unconstrained.
>   
This becomes non-issue if we straighten out (a), yes?
> c) provide a sufficient mechanism for those that care about the
> difference to determine that an information resource has been
> referenced.
>
> [btw: b) comes at the cost of c)]
>   
(c) is 303? If (a) is clarified, is 303 becomes unnecessary.
> None of this tells you what any given resource is - what a give
> reference actually denotes.
>   
Doesn't httpRange-14 implies this.  If 200, it is an information 
resource?  This is what starts off this thread.  Tim, requested by 
Jonahan and Alan, asked if any triple can be derived from HTTP response. 
> Well, in that case, rather than going round the houses, I suggest you
> propose an alternative defintion, bearing mind that in order for a
> definition to stick you'll need to reach concensus with a community that
> does care to distinguish information resource - or persuade them that
> the distinction is not worth making.
>   
I am hoping to persuade TAG to take this position. 
>> Why cannot. Assuming your past few email is posted to my 
>> website, wouldn't it possibly change the state of my mind? 
>>     
>
> But... can you convey your "state of mind" before and after our exchange
> in a message? :-)
>   
But isn't this just a matter of implementation detail?  I can convey a 
portion of it depending on your request.  When you send me an email, you 
have, in fact, manipulated my state of mind - through the mailto URI, 
yes? Of course, I can choose to change my mind or not.  Just like an  
HTTP server can decide to react, or not, to a POST request...
> Well, try as a I might, I don't think that I can affect the state of the moon by referring to it with an HTTP URI and doing a PUT or a POST.
> Equally, I very much doubt that it is going to yield a representation of
> itself however nicely I ask it.
>   
NASA, Russia or China, might just have one - a web interface with a 
click button to start a countdown for launching a missile to the moon.  
But if there is such a functionality is not the issue of web 
architecture.  For instance, I want to have the power to freely 
manipulate the URI that denotes my bank account.  I own the bank account 
but I don't own the URIs.  How the URI owner and me cooperate is 
governed by a different set of rules, such as policy, laws, morale, etc 
But none of this is set by the web architecture. 

Regards,

Xiaoshu
Received on Tuesday, 23 October 2007 15:06:38 UTC

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