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RE: fragment identifiers

From: Joshua Allen <joshuaa@microsoft.com>
Date: Tue, 23 Jul 2002 22:14:16 -0700
Message-ID: <4F4182C71C1FDD4BA0937A7EB7B8B4C105DCDA1A@red-msg-08.redmond.corp.microsoft.com>
To: "Jonathan Borden" <jonathan@openhealth.org>, "Graham Klyne" <GK@NineByNine.org>, "Roy T. Fielding" <fielding@apache.org>
Cc: <www-tag@w3.org>, <timbl@w3.org>

> one can draw no conclusions based on the syntax of the URI reference.
Tim
> says that "http" URIs ought only refer to _documents_ which makes some
> intuitive sense, but I've yet to hear a purely logical or pragmatic
reason
> why this must be the case -- e.g. what breaks if we allow something
like
> http://example.org/term/Car to refer to the concept "Car"? RDF would
be
> happy as a clam with this.

It's a "should", not a "must".  Systems that will "break" are systems
which assume that an http: identifier identifies a hypermedia resource
meant to be accessed via a web browser.

People SHOULD use http: identifiers only to refer to resources which
they intend to be accessed through HTTP.

Sorry to sound frustrated, but this is THE most important issue to the
semantic web.  There is nothing more important than agreeing on an
identification scheme that unambiguously (to the extent possible)
identifies things.  I have commented on this issue on my personal web
log:
http://www.netcrucible.com/blog/2002/07/20.html#a225


(Here is the exact same argument in human terms.  Sound like a Beckett
play, doesn't it?)
TimBL: People shouldn't say "bad" when they mean "good"
Roy:   But people CAN use "bad" when they mean "good"; I heard 
       Michael Jackson do that before.
TimBL: But, that's a dangerous thing to do.  It could cause 
       problems!
Roy:   Prove it!
Jon:   Roy's right, you know.  I heard Michael Jackson, too.  
       Besides, if someone misinterprets the word "bad" and thinks 
       it *really* means bad, then they made a mistake!
TimBL: That doesn't help the speaker much to say it's the 
       listener's fault!
Roy:   Well, that's the way it is.  Michael Jackson already opened
       Pandora's box, so "bad" CAN mean either "bad" or "good".
       Everybody *already* needs to deal with ambiguity if they want
       to be able to understand anything.
TimBL: But, *speakers* should strive for clarity if they want to
       be understood.
Dan:   But why constrain the speaker this way?  Axioms 1 and
       2a of web design [1] are trumped by "principle of least 
       constraint"
Kevin: Least constraint is no good!  I know sendmail technique!


[1] http://www.w3.org/DesignIssues/Axioms.html
Axiom 1: It doesn't matter to whom or where you specify that URI, it
will have the same meaning.
Axiom 2a: a URI will repeatably refer to "the same" thing
Received on Wednesday, 24 July 2002 01:14:51 GMT

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