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Re: 2.3 URI Ambiguity

From: Dan Connolly <connolly@w3.org>
Date: Tue, 02 Dec 2003 10:46:13 -0600
To: "Ian B. Jacobs" <ij@w3.org>
Cc: Tim Berners-Lee <timbl@w3.org>, Walden Mathews <waldenm@optonline.net>, www-tag@w3.org, "Williams, Stuart" <skw@hp.com>, Mark Baker <distobj@acm.org>
Message-Id: <1070383573.1663.105.camel@dirk.dm93.org>

On Tue, 2003-12-02 at 10:31, Ian B. Jacobs wrote:
> On Tue, 2003-12-02 at 10:39, Tim Berners-Lee wrote:
> > On Dec 1, 2003, at 14:15, Walden Mathews wrote:
> > 
> > > It seems to me that the Architecture of the World Wide Web
> > > has to make a decision as to whether there is such a thing as
> > > indirect identification at the architecture level, and if so formalize
> > > what that is.
> > 
> > The problem was just that when we said "only use URI to identify the 
> > one thing", a lot of people responded with a counter-example of the 
> > person "identified" by their mailbox.  So the counter-example was only 
> > in so as to say, "No, we don't mean that".   If we have to formalize 
> > everything that we don't mean, then we would end up  extending the 
> > architecture document indefinitely!
> > 
> > The only way i can think of of making it clearer is to use say NTriples.
> 
> What about something like this:
> 
>   "In Web architecture, URIs identify resources. Outside of Web 
>    architecture, the URI string can be useful in any number of
>    roles (e.g., as database keys), including as identifiers. For 
>    instance, "mailto:nadia@example.com" can be used by the organizers 
>    of a conference as an identifier for Nadia; parties involved in 
>    the context understand and agree to that local policy. Certain
>    properties of URI strings in the Web architecture, such as their
>    potential for uniqueness, make them appealing for non-Web contexts. 
>    In the Web architecture, "mailto:nadia@example.com" only
>    identifies an Internet mailbox. The URI is not ambiguous within
>    the Web architecture merely because the URI string serves different
>    roles in other contexts. URI ambiguity arises when an agent uses
>    the same URI to identify two different *Web* resources.

That appeals to me.

A nit: "URI strings" hmm... maybe that's OK... maybe not...

And I think it's better if you change "when an agent uses the same URI"
to "when the same URI is used", since it's also bad for *different*
agents to use the same URI for different web resources. In fact,
that's the whole point: the principle of anarchic scalability says
those two agents need to be able to communicate, or at least that
a third agent needs to be able to communicate with both of them.

Do we have the principle of anarchic communication in the arch
doc yet?

I have found it useful when noodling...
  http://esw.w3.org/topic/AnarchicScalability
(which cites Fielding's thesis
http://www.ics.uci.edu/~fielding/pubs/dissertation/introduction.htm)

> Notice there is no use of the phrase "indirect identification".
> 
>  _ Ian
-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Tuesday, 2 December 2003 11:46:14 GMT

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