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Re: web proper names

From: Harry Halpin <hhalpin@ibiblio.org>
Date: Mon, 20 Sep 2004 16:18:51 -0400 (EDT)
To: www-rdf-interest@w3.org
cc: ht@inf.ed.ac.uk
Message-ID: <Pine.LNX.4.44.0409201543440.1498-100000@tribal.metalab.unc.edu>

First, Web Proper Names can be used over the http URI space (which I,
moreso than Henry, am interested in), as per se the Expanded Web Proper 
Names part of the proposal. Thus, you could detect whether
a statement is about a "document" or a "subject" by inspecting the
representation returned. This actually inline with the TAG (as it stands),
and solves the problem point blank without either a new URI scheme
or new RDF predicates. One could just say:

http://www.w3.org/People/thompson/
http://purl.org/dc/elements/1.1/creator
http://www.ltg.ed.ac.uk/~ht/HenryThompson.wpn

And http://www.ltg.ed.ac.uk/~ht/HenryThompson.wpn returns a representation
inline with the RDDL document specified by the WPN paper. 
 
Comments in-line on other threads!

> The analogy is false IMO. Mentioning a URI is saying something like 
> "The  URI 'http://www.example.net/blah' has 27 characters, uses the common
> convention of naming a webserver 'www', has no query-string and doesn't
> > use any of character escapes defined in RFC 2396".

	Correct in one sense, wrong in the other. In the sense that
you are mentioning a URI without any reference to the resource it 
identifies, correct. However, the trouble appears 
that URIs are meant to *identify* resources. You can use a URI to refer 
to either the representation it can retrieve (*mention*, as in the 
word 'rice' in a sentece could be the representation of a bowl of rice on 
my table) or use the URI to refer to a thing itself (*use*, as in 
directly talking about the bowl of rice on my table). I don't see
anywhere in the specs where it says that's impossible - indeed, RDF,TAG
and the new URI draft encourage this behavior.
 
Jon's short explanation on the TAG mailing list dodges the question.

What people actually do is this:
<http://www.w3.org/People/thompson/> 
<http://purl.org/dc/elements/1.1/creator>
"Henry Thompson" 

But you cannot make many meaningful statements about the string "Henry
Thompson" since it doesn't have a URI. Thus, it would actually make sense
to use:

<http://www.w3.org/People/thompson/>
<http://purl.org/dc/elements/1.1/creator>
<http://www.ltg.ed.ac.uk/~ht>

But then *a machine* doesn't know whose web-page is talking about which 
man, or if it's two web-pages, or two men. Humans are good at this,
machines are bad. While it is *plainly* nonsense to a human, it is *not 
nonsense* to a  machine. The machine cannot read the purl.org docs. It can 
read RDF Schema, but there is no "subjectIsTheThingReturnedByThisURI" 
mechanism in place yet. If want "machine-readable" semantics, we
have to follow through with distinctions. For another take on this,
read Shelley's excellent write up of Pat Hayes and TimBL arguments
over this matter:

http://weblog.burningbird.net/archives/2003/07/24/context-and-meaning

                                                                             
> > Just because you get a representation when you do a particular action
> > with it no more makes that representation the thing the URI identify
> > than using my name in an enquiry makes "Jon Hanna" intrinsically bound
> > to "Quite tall, shaven head, wears black a lot". It certainly doesn't
> > make it bound to that and nothing else.
	
	Again, I would recommend reading the part about Kripke in the 
paper. That's the theory WPN is based on -> a referent such as the person
identified by "Jon Hanna" is going to be Jon Hanna even if he grows his
hair and wears bright yellow. That's why many of the parameters in
WPN are option.

	Again, I think Thomas Passim's solution of adding RDF predicates
is a good direction for thought:
1) subjectIsTheThingReturnedByThisURI
2) theDocumentAtThisUriDescribesTheSubject
3) theDocumentAtThisUriIsAboutTheSubject

Any debate on these? Still, Web Proper Names are meant to solve the 
problem in a RDF-neutral matter, and can solve via either a new URI
scheme or using a new format (RDDL-based) for representing things qua
things. Enjoying the discussion...

					-harry
Received on Monday, 20 September 2004 20:18:53 GMT

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