RE: URI for language identifiers

> -----Original Message-----
> From: ext Jan Algermissen [mailto:algermissen@acm.org]
> Sent: 02 April, 2003 10:46
> To: Stickler Patrick (NMP/Tampere)
> Cc: www-rdf-interest@w3.org
> Subject: Re: URI for language identifiers
> 
> 
> Patrick.Stickler@nokia.com wrote:
> 
> > 
> > But if the URI denotes two things, how do you differentiate
> > between statements made about one versus the other?
> 
> The URI does not denote two things. There are just two kinds 
> of properties
> on topics that use URIs as values. The semantics of the properties are
> different.
>
> The whole thing is different because in topic maps, you have 
> an unlimited
> number of possibilities to identify what a given topic represents.

Are you denoting topics using URIs or not? If you are, and that
topic can represent more than one thing, then that's ambiguous.

> > The key is knowing what it denotes, and that the denotation 
> is consistent.
> 
> So, how do I find out what it denotes?

You ask the owner of the URI, or you look for statements about the
resource made by the owner of the URI or resource.

And if you are unnable to clearly determine what that URI denotes,
then you simply are left without a clear answer, and shouldn't use
it.

> > > The denotation is not ambigous but there are two *ways to 
> use* of URIs
> > 
> > If a single URI can denote both a web resource and an 
> abstract subject,
> > then it is ambiguous. Period. 
> 
> A URI allways denotes the 'web page'. Period. ;-)

Then TM's are completely unusable for most of what I do if I
can't use a URI in a TM to denote an abstract concept.

> > If the interpretation of a give URI depends
> > on context, then it is ambiguous. Period. 
> 
> The context is explicit, so what is ambigous about that?

Where is the context explicit? If all I have is a URI, and
nothing else, how to I determine which of the many possible
things it might denote in a TM?

If I ask some knowledge base "Tell me about the thing denoted
by this URI" what is it going to tell me? Is it going to 
describe all the possible things it could denote? The web
page, the subject, whatever?

URIs should have consistent, *global* (meaning context-independent)
and unambiguous denotation. Period.

If XTM doesn't provide that, then it is inherently incompatible
with RDF.

> > XTM has ambiguous use of URIs.
> 
> No. Period. ;-)

Sorry. You seem to be mistaken here. If you understand what
"globally unambiguous" means.

XTM does not appear to use URIs in a globally unambiguous manner.

 
Patrick

--
Patrick Stickler, Nokia/Finland, (+358 40) 801 9690, patrick.stickler@nokia.com

Received on Wednesday, 2 April 2003 03:30:36 UTC