W3C home > Mailing lists > Public > www-tag@w3.org > June 2006

Re: CURIEs: A proposal

From: Harry Halpin <hhalpin@ibiblio.org>
Date: Tue, 27 Jun 2006 22:24:08 +0100
Message-ID: <44A1A1F8.4060000@ibiblio.org>
Cc: W3C TAG <www-tag@w3.org>



     Just to clarify, to me Roy seems to be saying that "all URIs *can*
become dereferencable (although perhaps in a nonstandard manner) - which
is true, but then is following it up with saying that any _Web
architectural knowledge_ encoded in a scheme *should* be dereferencable.

>> All URI schemes become dereferenceable as soon
>> as someone can map any representation associated with the resource to
>> a mechanism that accepts a string and returns a representation.
>> That doesn't change the principle that namespace names should be
>> dereferenceable *because* Web architectural knowledge should be
>> grounded in the Web.
Given the fact that any scheme *can* become capable of dereference, it
makes little sense to argue that namespace names of anything should use
a scheme whose purported advantage (like URN) is their
non-dereferencability. Instead, given that one can dereference anything
in theory, one should at least use a URI with a dereferencing mechanism
that is standardized and widely deployed *in practice* like http.   By
underlining "Web architectural knowledge" - anything that's important to
the Web as a whole, like MIME types,  should obey the informal "Follow
Your Nose" principle and have its description be found on the Web, not
just in say, a book somewhere or a spec with no connection to a URN :)
That's sensible.
>   Similarly, most of the uses of URIreferences in semantic web
> formalizations are at best tangential to this principle, since their
> intended Web functionality has nothing to do with dereferencing, and
> allowing them to be dereferenced has only produced difficulties and
> controversy, and adds nothing to their utility
Pat and Noah are correct here - turning into a rule instead of good
practice would be overkill, as URIs are often used for names without an
obvious dereferencing function. The question is - if one had a a
namespace URI or a SemWeb URI, and did dereference *something* at the
end of it, does this help? Re the SemWeb, right now it does seem to be
causing more trouble and confusion than good, but we recently put a
workshop on to see if anything good could come out of this, and Pat has
some interesting slides, as well as Steve Pepper available from the
website [1].

There is a cost-benefit trade-off function when dealing with creating
representations for the numbers of Semantic Web URIs and namespace
documents, and part of the whole problem is that there's no clear
standard for best practice for namespace documents or what a Semantic
Web URI could return, much less tools to make the creation of such
things trivial as to make the benefit higher than the cost.
> Why 'must' this 'principle' be stated or even used?
It helps  to make the Web be "self-describing", although the notion of
"self-describing" is something I think is another notion that could
really use some inspection.

[1] http://www.ibiblio.org/hhalpin/irw2006/

-- 
		-harry

Harry Halpin,  University of Edinburgh 
http://www.ibiblio.org/hhalpin 6B522426
Received on Tuesday, 27 June 2006 21:24:25 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Thursday, 26 April 2012 12:47:41 GMT