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Re: What if two resources are the same subject?

From: Jon Hanna <jon@hackcraft.net>
Date: Tue, 13 Apr 2004 19:01:56 +0100
Message-ID: <1081879316.407c2b149e639@82.195.128.192>
To: "www-rdf-interest@w3.org" <www-rdf-interest@w3.org>

Quoting Jan Algermissen <jalgermissen@topicmapping.com>:

> My first question is what happens when RDF statements from both camps are
> combined
> and people start noticing that there are two resources being the same thing
> (Canada).

Well there is only one resource, but multiple URIs, which is no different to my
being called "Jon Hanna", "Jonathan Hanna" and "Talliesin" by different
people.

> Is there any mechanism to at least note that fact? Is there an RDF schema
> that
> provides the semantics to say that several resources actually are the same
> thing?

owl:sameIndividualAs

> From a Semantic Web-user's perspective: How do I find out statements about
> Canada?
> How do I know which URL to use or supposed I know both, can I use any of them
> or do
> I have to submit my 'questions' once for every URL?

You can use either. If your tools know that
<http://www.some.org/countries/canada> <owl:sameIndividualAs>
<http://another.org/public/countries/Canada> . Then they can do the necessary
leg work for you.

Of course sometimes there can be subtle differences (e.g. "Ireland" the island
vs. "Ireland" the country) and sometimes those differences can be contentious
(e.g. Ireland again).

You do need to "know" that they two URIs identify the same resource. Sometimes
this will be published somewhere (ideally either or both URIs when dereferenced
would reveal this fact). It might not be that easy to determine though, it
might even be secret (Superman owl:sameIndividualAs Clark Kent, but he doesn't
want anyone to know :)


-- 
Jon Hanna
<http://www.hackcraft.net/>
"…it has been truly said that hackers have even more words for
equipment failures than Yiddish has for obnoxious people." - jargon.txt
Received on Tuesday, 13 April 2004 14:02:00 GMT

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