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Re: What if an URI also is a URL

From: Tim Berners-Lee <timbl@w3.org>
Date: Mon, 11 Jun 2007 14:32:45 -0400
Message-Id: <508D7C9D-9AE2-4C4D-A557-AB3B2CE6EB4B@w3.org>
Cc: "M.David Peterson" <m.david@xmlhacker.com>, "r.j.koppes" <rikkert@rikkertkoppes.com>, "Yuzhong Qu" <yzqu@seu.edu.cn>, "Sandro Hawke" <sandro@w3.org>, <semantic-web@w3.org>, <swick@w3.org>, <phayes@ihmc.us>
To: "John Black" <JohnBlack@kashori.com>

On 2007-06 -11, at 13:53, John Black wrote:

> Tim Berners-Lee wrote
>> On 2007-06 -09, at 21:22, M. David Peterson wrote:
>>> On Sat, 09 Jun 2007 07:13:52 -0600, Tim Berners-Lee <timbl@w3.org>
>>> wrote:
>>>> No. It cannot identify both a document and a person.
>>> Tim: Will all due respect... WTF?
>> I am using the 'identify' in the strict sense of 'denote'.
>> The semantic web is like a logic language in which URIs are symbols.
> Do you believe that by claiming to use the strict, logical sense of  
> the word 'denote' you thereby cause or require such denotations to  
> be absolute and unambiguous? Where do think denotations (or  
> identifications) come from?

The architecture is that each URI is owned.   With HTTP URIs, this  
happens through the domain name system and often  delegation within a  
domain. Unlike a word, a URI has an owner.  The owner attempts to  
make enough information available that the URI can be used by others  
without ambiguity in practical situation.

For example, W3C owns http://www.w3.org/People/Berners-Lee/card#i and  
has delegated to me the right to say what that URI stands for. To use  
it for something else is an error.

> In my opinion to denote (or to identify) is a verb, something that  
> is done by the users of a symbol. After all, symbols (URI) are not  
> agents, they don't wake up and choose to denote this or that.

They have wonders which create them for a specific purpose.

> Nor do I think denotation is an attribute or property of a symbol,  
> somehow built in or attached when the symbol is first conceived. It  
> is more like a dance. I use a symbol to denote something expecting  
> you to interpret it to denote the same thing. And this  
> coordination, this synchrony of interpretation by both sender and  
> receiver, is not always easy. It requires real effort to sustain  
> it. The minter of a URI cannot make it happen by declaration, nor  
> can a research group or a standards body just decree it so.

In many cases, the URI is defined by connection to already well- 
defined sets of things.  In other cases, such as the terms in the OWL  
ontology, there was a huge amount of effort and discussion involved,  
and the current term is supported by a lot of ongoing tutorials and  
so on.  No one said it was easy.  But it is a different architecture  
from dance associated with natural language words.

It is different by design.  The semantic web is an engineered system,  
not an observation of nature.

> The reason this matters is that since it requires this effort to  
> create a denotation/identification in the first place, it is far  
> more sensible, to me at least, to expect that the final  
> disambiguation of a symbol be accomplished in the same way, by  
> coordinated effort of the parties using the symbol, not by  
> declaration of the W3C specifications that all URIs be absolutely  
> unambiguous.
> This seems to me to be, as my grandfather used to say, a vain task.

Your grandfather would perhaps have suggested that an attempt to  
define the meaning of common words, as the Académie Française is set  
up to do were a 'vain task'.   Many would agree.  But given that his  
water came to him though pipes connected, possibly, by half-inch  
British Standard pipe-thread connections, and he rode on rails set a  
certain distance apart by some committee, and his TV came for better  
or worse in 525 or 625 lines as decided by other committees, he may  
have respected that the creation of standards is a very valuable  
function, and an essential to progress.

When people meet to define W3C specifications they are not doing it  
out of vanity.   They are performing coordinated effort of the  
parties who would like to be able to use the symbol.  They are, in  
general, users and representatives of users of the symbol.   They  
come together to allow those who follow them to use it. They often  
work long hours, receiving inadequate recognition for either products  
shipped or papers published, the conventional metrics of performance,  
so I would not call it vanity.

Note also that W3C (IETF, etc) specs have achieved a lot, made a lot  
of interoperable systems, and formed with each layer a foundation for  
building new layers. So I would not say that the work as been in vain  

Received on Monday, 11 June 2007 18:32:48 UTC

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