Re: URI resolver was Re: RDDL and XML Schemas Proposed Recommendation

[Michael Mealling <michael@bailey.dscga.com>]

On Sun, Mar 25, 2001 at 01:37:12PM -0800, Tim Bray wrote:
> At 10:14 AM 25/03/01 -0500, Michael Mealling wrote:
> >Jonathan Borden wrote:
> >> Using RDF you can make statements about URIs that cannot be
> >> disproven by resolving the URI -- indeed there is no guarentee nor even
> >> intention that a URI _can_ be resolved.
> >
> >RDF can do this, sure. But URIs don't know or care about RDF. RDF
> >is simply one of a multitude of applications that use URIs. Each
> >application uses them differently. In RDF's case it uses URIs to make
> >some interesting and complex statements about URIs but that doesn't
> >mean that URIs then inherit those statements. 
> 
> I think you guys are straining at gnats.  What RDF does is 
> entirely appropriate, and it is a useful thing to make assertions
> using URIs as hooks.  The subtleties about "resolution" are
> lost on most people, which is I think just fine.

While it may be safely lost on people (users?), if its lost on system 
designers you get huge interoperability problems....

> The popular notion is that a UR* corresponds to some 
> thingiedoohickeywhatever out there and here's an assertion about it.  
> No, it doesn't affect the thingiedoohickeywhatever of course, and 
> indeed it might not be true or even relevant.  But the R in UR? 
> stands for Resource, and there's a widely-held popular notion of 
> what a resource is perhaps best expressed in some old W3C doc as 
> "a Web-addressible unit of information or service", and this is 
> plenty accurate enough to be useful.
>
> I fail to grasp the practical implications of the points being
> debated here. -Tim

Yes it does sound academic but its this exact subtlety that caused
so much consumed bandwidth over the XML Namespaces issue. It is
very tempting to say things like "I should be able to tell if
two URIs identify the same resource" but what you find is that
if you don't pay attention to the subtleties in that assertion you
end up with a system that breaks a large number of applications very
quickly.

It all goes back to that question: What does a URI identify and 
is that relationship 1:1? I think there's consensus but if you're
not careful about your language you can end up exactly where we were...

-MM

-- 
--------------------------------------------------------------------------------
Michael Mealling	|      Vote Libertarian!       | www.rwhois.net/michael
Sr. Research Engineer   |   www.ga.lp.org/gwinnett     | ICQ#:         14198821
Network Solutions	|          www.lp.org          |  michaelm@netsol.com