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Re: OWL and LOD

From: Toby Inkster <tai@g5n.co.uk>
Date: Tue, 12 May 2009 11:59:29 +0100
To: Steve Harris <steve.harris@garlik.com>
Cc: John Goodwin <john.goodwin@ordnancesurvey.co.uk>, public-lod@w3.org, semantic-web@w3.org
Message-Id: <1242125970.15673.27.camel@ophelia2.g5n.co.uk>
On Tue, 2009-05-12 at 11:37 +0100, Steve Harris wrote:
> I was thinking more of this issue:
> http://lists.w3.org/Archives/Public/semantic-web/2009May/0071.html
> re. slide 26. I've seen this done too, and it's quite concerning.

owl:sameAs is a very blunt tool and rarely useful. Instead we should be
thinking about domain-specific equivalency predicates.

Take for example:

	1. <http://tobyinkster.co.uk/#i>
	2. <http://www.doc.ic.ac.uk/~tai99/foaf.xml#me>

Both are URLs representing me -- the first is recent and kept up to
date; the second is a much older URL that 404s and I'm no longer able to
update.

Depending on what you're doing, it might be useful to treat these two as
equivalent. If you have information on [2]'s blood type, then it's
probably equally applicable to [1].

But for other purposes it's useful to treat them separately. The marital
status of [1] and [2] differ, as do their interests, their e-mail
addresses and various other details.

This is where equivalency predicates come in. It might be useful, for
example, to have a foaf:samePersonAs predicate to allow us to assert
that two URLs represent the same person, but still not glue them
together as tightly as owl:sameAs does, so that we can still make
statements about them individually.

I don't know if OWL2 could then allow us to then define which of our
favourite predicates can be cross-applied between two resources which
are foaf:samePersonAs each other, and which may differ. (I don't think
OWL1 is capable of that.)

-- 
Toby Inkster <mail@tobyinkster.co.uk>
Received on Tuesday, 12 May 2009 11:00:15 GMT

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