imported>Denny at 02:42, 28 December 2007

2007-12-28T02:42:18Z

imported>Denny: New page: {{pubdate|5|January|2005}} Last time we merrily published our first statement for the Semantic Web:

http://www.imdb.com/title/tt0088247/ http://purl.org/dc/elements/1.1/creator "Jame...

2007-12-27T19:28:11Z

New page: {{pubdate|5|January|2005}} Last time we merrily published our first statement for the Semantic Web: <pre>http://www.imdb.com/title/tt0088247/ http://purl.org/dc/elements/1.1/creator "Jame...

New page

{{pubdate|5|January|2005}}
Last time we merrily published our first statement for the Semantic Web:

<pre>http://www.imdb.com/title/tt0088247/ http://purl.org/dc/elements/1.1/creator "James Cameron".</pre>

A fellow Semantic Web author didn't like the number-encoded IMdb-URI, but found a much more compelling one and then published the following statement:

<pre>http://en.wikipedia.org/wiki/The_Terminator http://purl.org/dc/elements/1.1/date "1984-10-26".</pre>

A third one sees those and, in order to foster integration of data offers helpfully the following statement:

<pre>http://www.imdb.com/title/tt0088247/ owl:sameAs http://en.wikipedia.org/wiki/The_Terminator.</pre>

And now they live merrily ever after. Or do you hear the thunder of doom rolling?

The problem is that the URIs above actually already denote something, namely the IMdb website about the Terminator and the Wikipedia-article on the Terminator. They did not denote the movie itself, but that's how they're used in our examples. Statement #3 above actually says the two websites are the same. The first one says, that ''"James Cameron"'' created the IMdb website on the Terminator (they'd wish), and the second one says that the Wikipedia article was created in 1984, which is wrong (July 23, 2001 would be the correct date). We have a classic case of URI collision.

This happens all the time. People working professionally on this do this too:
<pre>_person foaf:interest http://dmoz.org/Computers/Security/.</pre>

I'd bet, ''_person'' (remaining anonymously here) does not have such a heavy interest in the website ''http://dmoz.org/Computers/Security/'', but rather in the Topic the website is about.

<pre>_person foaf:interest _security.
http://dmoz.org/Computers/Security/ dc:subject _security.</pre>

Instead of letting ''_security'' be anonymous, we'd rather give it a real URI. This way we can reference it later.

<pre>_person foaf:interest http://semantic.nodix.net/topic/security.
http://dmoz.org/Computers/Security/ dc:subject http://semantic.nodix.net/topics/security.</pre>

But, oh pain - now we're exactly at the same spot we've been in the last part. We have an URI that does not dereference to a website (by the way, I do know that the definition of ''foaf:interest'' actually says the semantics of ''foaf:interest'' is, that the Subject is interested in the Topic of the Object, and not the Object itself, but that's not my point here)<br />
Thinking for a moment about it, we must conclude that it is actually impossible to achieve both goals: either the URIs will identify a resource retrievable over the web and are thus unsuitable as URIs for entities outside the web (like persons, chairs and such) because of URI collision, or they don't - and will then lead to 404-land.

Isn't there any solution? (Drums) Stay tuned for the next exciting installment of this series, introducing not one, not two, not three, but four solutions to this problem!

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What's in a name - Part 3 - Revision history

imported>Denny at 02:42, 28 December 2007

imported>Denny: New page: {{pubdate|5|January|2005}} Last time we merrily published our first statement for the Semantic Web:
http://www.imdb.com/title/tt0088247/ http://purl.org/dc/elements/1.1/creator "Jame...