RE: isDefinedBy and isDescribedBy, Tale of two missing predicates

Nathan

One practical downside of hash URIs that I've come across is this:

Suppose I have a resource http://example.com#foo

I can provide a description of it at http://example.com - so far so good.

If someone then asks me about http://example.com#bar - for whatever reason - but in fact I don't know anything about that identifier, in the sense that I don't have any statements about it in my triple store.  I'd like to tell that fact to the user - by returning 404 say,  but in fact my only option is to return the description of a different resource http://example.com#foo.  It won't be wrong, but it's a bit like saying "describe Paris to me" and getting the answer "well Milan is very nice this time of year".

It's not the end of the world and you can work round it with conventions - for example by always using the same hash fragment of #thing etc

By the way, I like the hash fragment approach for ontologies, concept schemes etc and tend to use them in that context.

Sorry don't really want to derail this discussion into a hash vs slash rehash :-)

Bill



-----Original Message-----
From: public-lod-request@w3.org on behalf of Nathan
Sent: Fri 11/5/2010 1:43 PM
To: Dave Reynolds
Cc: Kingsley Idehen; public-lod@w3.org
Subject: Re: isDefinedBy and isDescribedBy, Tale of two missing predicates
 
Dave Reynolds wrote:
> Clearly simply using # URIs solves this but people can be surprisingly
> reluctant to go that route.

Why? I still don't understand the reluctance, any info on the technical 
non-made-up-pedantic reasons would be great.

Best,

Nathan