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Re: Uniform access to descriptions

From: Pat Hayes <phayes@ihmc.us>
Date: Wed, 9 Apr 2008 15:50:50 -0500
Message-Id: <p06230905c422cecdf7f2@[]>
To: wangxiao@musc.edu
Cc: "Williams, Stuart (HP Labs, Bristol)" <skw@hp.com>, Jonathan Rees <jar@creativecommons.org>, "www-tag@w3.org WG" <www-tag@w3.org>, Phil Archer <parcher@icra.org>
At 7:15 PM +0100 4/9/08, Xiaoshu Wang wrote:
>Pat Hayes wrote:
>>>>>If I don't know what is an IR, how do I judge what it isn't? 
>>>>>This is essentially what Tim responded to my question.  He said: 
>>>>>well !IR <> non-IR.  Then, what is the intersection of IR and 
>>>>>non-IR.  This is not an answer, this is to avoid answer and then 
>>>>>it is useless, don't you think so?
>>>>No. The world is full of cases of concepts which have clear 
>>>>examples and non-examples but which are very hard to specify near 
>>>>their edges, so very hard to give exact definitions for. Colors 
>>>>are the often-cited canonical example. There are reds which 
>>>>everyone will agree are red and blues which everyone will agree 
>>>>are non-reds, but near the red/orange boundary nobody will agree, 
>>>>even with themselves from day to day. Natural concepts often 
>>>>resist precise definitions. That doesn't stop them being 
>>>>extremely useful, however.
>>>Pat, I see the problem now.  We agree on that there is no clear 
>>>distinction for IR.  So, let's don't argue in that direction.
>>>My question is very clear and precise.  Do you agree to invoke 
>>>such logic in the web.
>>>If HTTP(x)=200, x=IR
>>>If HTTP(x)=303, x=?
>>>Here is the multiple choice
>>>(1): Yes.   (1a) The distinction between 200-303 is important. 
>>>(Then, it is you who is trying to make a clear distinction, not 
>>>   (1b) The relationship between 303 and 200 is not important. 
>>>Hence, 200 and 303 becomes irrelevant and therefore httpRange-14.
>>>(2).  No.  then, any discussion between 200 and 303 is moot and 
>>>therefore httpRange-14.
>>>Tell me your position.  My position is very clear - that is (2). 
>>>Otherwise, I don't know if you are defending for or against my 
>>OK, I will have to go for 1a, then. I wish I didn't have to, and I 
>>don't like it, but I see no other feasible choice at present. If 
>>someone comes up with one I'll be delighted to hear it. If the 
>>Semantic Web were smart enough to handle URI ambiguity the way that 
>>human language handles lexical ambiguity, there would be no 
>>problem; but right now it isn't, and it probably won't be for some 
>>time to come. So we have to do something simpler and cruder.
>I don't understand the logic you give.  You want 200=IR.

Yes. It seems kind of obvious that a normal bare URI should denote 
whatever it identifies. This became a kind of de facto standard usage 
on the semantic web without anyone saying so explicitly, almost by 
osmosis; and it seems to work so far very well, with only a very few 
exceptions (notably dublin core) all of which were very early 
(pre-SWeb, in effect) and can be forgiven for being slightly off base 
for a while.

>  But then you wish the "=" is not necessarily hold?  Where it is 
>going? Then are you rejecting or accepting 200=IR or not? Or you 
>take the "=" as a paradox, which is neither true nor false?

No, of course not. And as you probably know, I was vociferously 
opposed to http-range-14 for quite a long time. I still dislike the 
idea of using http codes to convey semantic information. But I don't 
see any other practicable route out of the dilemma that we find 
ourselves in.

You propose a new code, which I agree is more elegant than re-using 
303. But it still uses http codes, which is the part I really don't 
like; and I get the impression that it simply wouldn't be politically 
practical to make such a drastic change to the http spec just for 
this issue, when 99% of the Web doesn't even know what 'semantics' 
means. And the re-use of 303 is kind of harmless, as only the 200 
code 'conveys' any information at all, and all it conveys is that for 
this URI, 'identification' and denotation are aligned: it denotes 
what it identifies, whatever that is. I have never been entirely 
clear what exactly is 'identified' by a URI, or what an 'information 
resource' is (html document? Webpage? Website? HTTP endpoint?) but 
that doesn't seem to matter: I get what I get, and the Web works OK 
without answering such metaphysical questions.



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Received on Wednesday, 9 April 2008 22:51:54 UTC

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