W3C home > Mailing lists > Public > www-rdf-interest@w3.org > September 2004

RE: web proper names

From: <Patrick.Stickler@nokia.com>
Date: Tue, 21 Sep 2004 12:02:54 +0300
Message-ID: <1E4A0AC134884349A21955574A90A7A50ADCC4@trebe051.ntc.nokia.com>
To: <henry.story@bblfish.net>, <www-rdf-interest@w3.org>
Cc: <h.halpin@ed.ac.uk>, <ht@inf.ed.ac.uk>



> -----Original Message-----
> From: www-rdf-interest-request@w3.org
> [mailto:www-rdf-interest-request@w3.org]On Behalf Of ext Henry Story
> Sent: 20 September, 2004 16:29
> To: www-rdf-interest@w3.org
> Cc: h.halpin@ed.ac.uk; ht@inf.ed.ac.uk
> Subject: web proper names
> 
> 
> 
> I have just come across a very well written paper by Harry Halpin and 
> Henry S. Thompson called "Web Proper Names: Naming Referents on the 
> Web" [1]. I don't feel comfortable with the proposed solution to the 
> problem, but I do feel he has described the problem itself very well, 
> and given a very good summary of the philosophical debate behind it.

Caveat: I've not yet read the above referenced paper. Given the authors,
I have no doubt that it is indeed well written. My comments below are
restricted to the contents of your post only.

> In particular the use/mention distinction has really helped locate a 
> problem that has kept bugging me when thinking about rdf.
> 
> This can be summarized by considering the following triples which 
> though formally contradictory, can in fact be seen to be compatible:
> 
> (A)     http://www.paris.org/Monuments/Eiffel
>              http://purl.org/dc/elements/1.1/creator
>          http://www.gustaveeiffel.com/
> 
> (B)     http://www.paris.org/Monuments/Eiffel
>              http://purl.org/dc/elements/1.1/creator
>          http://www.endex.com/gf/
> 
> If we only understand the above names to be used then the two 
> sentences 
> are contradictory.
> 
> (A) states that the Eiffel Tower was created by Gustav 
> Eiffel, whereas 
> (B) states that
> it was created by Gary Feuerstein. (A) is true in this 
> interpretation, 
> whereas (B) is false.
> 
> But we can guess that what was probably intended by (B) was not that 
> <http://www.paris.org/Monuments/Eiffel> refer to the Eiffel 
> Tower, but 
> that it refer to the Web Page which refers to the Eiffel 
> Tower, whereas 
> in the first sentence we have the intuition that it refers to the 
> actual building located in Paris.

Then someone is misusing the URI http://www.paris.org/Monuments/Eiffel. It's
as simple as that.

URIs should not be used to denote more than one thing. Period.

If you need to talk about two distinct things (the monument and the
web page describing the monument) then simply use two distinct URIs.

I don't see any fundamental architectural "problem" in the example above. 
Only an error in practice.


> Harry's solution is to assume that rdf resources by default point to 
> the representation of the resource and not the thing itself, 

One may make this assumption, and yet be wrong. Only the creator of
a URI can say what it denotes. And to use that URI to refer to anything
else is socially unacceptable behavior. People should respect the denotation
of a URI assigned by the creator of that URI. If the denotation is not
clear, then either (a) ask the creator to clarify the denotation, or (b)
don't use that URI. IMO, this is the foundation of responsible social
behavior on the web and semantic web.

> and then 
> to add a new wpn:// scheme to help create names that refer 
> directly to 
> an object. 

No new URI scheme is necessary. *ANY* URI is just fine for
denoting any resource. All that the wpn: scheme will do is
limit the web-accessibility of representations of the denoted
resource.

Just use distinct http: URIs to denote your resources (whatever
those resources are) and you'll be much better off.

> It occurs to me right now that from a philosophical 
> perspective this cannot quite be the correct solution, since the 
> arguments have always been that names can be used in both ways. So 
> whatever naming scheme one comes up with the problem of which 
> way they 
> are being used will exist.

Not if folks employ proper social manners and respect the denotations
assigned by the creators of URIs. 

Wherever there is ambiguity about the denotation of a name, there
will be confusion. The solution is to clarify the denotation, and
where necessary, mint and employ new names to reinforce that 
clarification.

The problem is not in the names themselves, or how we construct
those names (lexically/syntactically) but in the way people
use the names -- and that is a social/behavioral problem, not a
technical one; and therefore, the solution is social, not technical.

> Would it perhaps not be easier to extend RDF so that one can 
> point to a 
> resource in either way, for example by allowing the following:
> 
> <Entry rdf:about="http://www.paris.org/Monuments/Eiffel">
> or
> <Entry rdf:refers="http://www.paris.org/Monuments/Eiffel">

No.

Just use another URI if you want to talk about something else, and
if you like, relate the two resources accordingly:

<http://www.paris.org/Monuments/Eiffel>
   rdf:type
      ex:PhysicalEntity ;
   rdfs:comment
      "The Eiffel Tower" ;
   ex:hasRepresentation
      <http://www.paris.org/Monuments/Eiffel.html> .

<http://www.paris.org/Monuments/Eiffel>
   rdf:type
      ex:WebPage ;
   rdfs:comment
      "A Web Page about the Eiffel Tower" ;
   ex:representationOf
      <http://www.paris.org/Monuments/Eiffel> .

 
Regards,

Patrick

--

Patrick Stickler                (+358 40) 801 9690
Senior Architect                Hatanpäänkatu 1
Forum Nokia Web Services        33900 Tampere FINLAND
Nokia Technology Platforms      patrick.stickler@nokia.com

Forum Nokia is Nokia's online community for third party developers
creating mobile applications. Registered members can find a wide
range of development tools, supporting documents, and can meet other
developers on-line. The Forum Nokia site was established in 1995
and has currently over 1 500 000 members.

Forum Nokia                   http://www.forum.nokia.com
Register Online               http://www.forum.nokia.com/register
Info on Developer Platforms   http://www.forum.nokia.com/platform
Check the Latest Devices      http://www.forum.nokia.com/devices
Get the Latest Tools          http://www.forum.nokia.com/tools
Read the Latest Documents     http://www.forum.nokia.com/documents
Sell Your Applications        http://www.forum.nokia.com/business
Get Technical Support         http://www.forum.nokia.com/support
Get information on Testing    http://www.forum.nokia.com/testing
Give Feedback                 http://www.forum.nokia.com/feedback
Search/Browse Resources       http://www.nokia.com/search3
Received on Tuesday, 21 September 2004 09:04:19 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:52:09 GMT