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Re: HTTP URIs and authority

From: Pat Hayes <phayes@ihmc.us>
Date: Tue, 23 Oct 2007 16:51:42 -0500
Message-Id: <p06230917c3440bea1f49@[]>
To: noah_mendelsohn@us.ibm.com
Cc: wangxiao@musc.edu, Alan Ruttenberg <alanruttenberg@gmail.com>, Mikael Nilsson <mikael@nilsson.name>, Richard Cyganiak <richard@cyganiak.de>, W3C-TAG Group WG <www-tag@w3.org>, www-tag-request@w3.org

>Xiaoshu Wang writes:
>>  I think you still do.  You own the URI but you don't own Paris.
>  > What people gets back is your personal "impression" of Paris.

Noah Mendelsohn:

>Yes, if I say that the URI identifies my personal impression of that city,
>no if I say that it identifies the city itself.  Of course, with any
>resource, there is the question of the care I take in implementing its
>responses on the Web.  Representations can come back with erroneous
>information for all sorts of reasons, including sloppy coding, faulty
>hardware, etc.  One of those reasons is that I just wasn't careful in
>researching the population number that I offered. That doesn't make the
>URI identify my "impression" of Paris; if I say it identifies the city
>itself, then it does.

This is a very deep area in philosophy of language. What seems to me 
to be the central issue is, how do we fix reference? In order for two 
agents to communicate about referents, there has to be some degree of 
mutual agreement about the facts. If the two views of the world are 
too disparate, its impossible to say whether they are talking about 
the same thing or not. In ordinary language we usually take this for 
granted much of the time, but there can be cases where it goes wrong. 
Imagine the following conversation for example:

A: I like Paris.
B: Me too. That archway, for example, so magnificent.
A: Yes, the Arc de Triomphe...
B: No, the Brandenberg Gate, I think its called.

Clearly something is going wrong: but what? Does B have the wrong 
referent for "Paris"? Or for "Brandenberg Gate"? Or is he just 
confused about the facts of the case, and thinks the Gate is in the 
wrong city? There is no way to tell without more conversation. For 

A: The Brandenberg Gate is in Berlin, the capital city of Germany.
B(1): Paris is the capital city of Germany!
B(2): No, its in Paris, about 4 kilometers from the Eiffel Tower. Its 
a big arch in the middle of a traffic circle.
B(3): No, its in Paris, about 4 kilometers from the Eiffel Tower. Its 
a huge thing with six columns and a chariot on the top of it.
B(4): Berlin and Paris are the same place. The German-speakers call 
it one thing, the French-speakers another.

B1 seems to think "Paris" refers to Berlin; or, he may just think 
that Paris is in Germany. B2 probably thinks "Brandenberg Gate" 
refers to the Arc de Triomphe. B3 seems to know what "Paris" and 
"Brandenberg Gate" refer to, but he's got his facts wrong; but it is 
hard to be sure. B4 is so completely confused about Europe that its 
hard to know what he thinks these names refer to.

I don't think there is any way to determine what exactly someone 
(including a Web page or an OWL ontology) is referring to, other than 
to presume that they share enough assumptions with you that their 
names make sense; and to be ready to back off from that presumption 
when things break down. But there isn't a clear distinction, IMO, 
between saying that the other person has the referent right but the 
facts wrong, and saying that it has the referents muddled. B4, above, 
might know quite a lot about Paris and about Berlin and have all 
these individual facts correct, and still be under the illusion that 
they are the same city. What do we say in a case like this?


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Received on Tuesday, 23 October 2007 21:52:05 UTC

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