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Re: removing constraints on 'resource' [024-identity]

From: Martin Duerst <duerst@w3.org>
Date: Tue, 15 Jun 2004 11:54:41 +0900
Message-Id: <>
To: Pat Hayes <phayes@ihmc.us>, Tim Berners-Lee <timbl@w3.org>
Cc: Dan Connolly <connolly@w3.org>, Stuart Williams <skw@hp.com>, uri@w3.org, Tim Bray <tbray@textuality.com>, Joshua Allen <joshuaa@microsoft.com>, msabin@milessabin.com

Hello everybody,

I'm writing this mail in the hope that we can move forward on this
and finally complete the work on the URI spec update.
(even if I know that I risk to stir things up a bit)

At 16:01 04/05/27 -0500, Pat Hayes wrote:
>>On May 27, 2004, at 11:02, Pat Hayes wrote:
>>>BTW, the diagram cited below (Im looking at the one at 
>>>http://www.w3.org/DesignIssues/diagrams/URI-space.png ) directly 
>>>embodies that confusion/ambiguity very clearly. There are two black 
>>>arrows at the bottom, one going from 'hypertext' to 'anchor', the other 
>>>going from 'semantic Web' to 'anything'. THESE TWO RELATIONSHIPS 
>>>identification on a network, and belongs in my "C' category: the second 
>>>arrow is denotation, which has nothing to do with computation and 
>>>belongs entirely in the D category.
>>Yes.  The first is hypertext architecture; the second is semantic web 
>Well, its actually SWeb semantics. Im not sure that semantics and 
>architecture are the same kind of thing.
>>  They are different.
>>A warning: read the diagram carefully: it is not a venn diagram of 
>>resources, but of URIs.
>>Sets -- subset of URIs -- are labeled in roman text, or typewriter text 
>>with syntactic constraints such as URI scheme.  Then, some regions in the 
>>diagram are annotated in italic with some examples of the things which 
>>can be *identified by* those URIs.
>Ah. Ok, then my point is better stated thus: there are two different 
>senses of 'identify' being used here. The sense in which an XHTML 
>URI+localId "identifies" an anchor is not the same as that in which an RDF 
>URI+localId "identifies" whatever it denotes.  One single URI+localID 
>could identify an anchor in one sense and also refer to something 
>completely different in the second (SWeb) sense.  The two relationships of 
>'identification' have nothing particular to do with one another, a priori.

Yes. So this seems to look like an important distinction that should
carefully be reflected in the draft. But after further thinking, I got
to a different conclusion:

The basic idea of URIs is that they allow to use a single space of
'identifiers' to be used for all kinds of things, systems, operations,
concepts, what not. This has huge advantages, because it can produce
huge synergies and network effects. It also has clear limitations,
not everthing works with everything
(ever used a mailto: URI in an html:img src attribute?).

The Web and the Semantic Web are clearly very important uses
for URIs. But should they, or will they, be the only uses?
I hope not. So I think that rather than making distinctions
that we can agree are very important for some usages of URIs,
I think we should try to stay as general as possible.

Regards,    Martin.
Received on Monday, 14 June 2004 22:55:24 UTC

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