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Re: modelling issue?

From: David Booth <david@dbooth.org>
Date: Mon, 05 Oct 2009 13:35:58 -0400
To: Paola Di Maio <paola.dimaio@gmail.com>
Cc: semantic-web at W3C <semantic-web@w3c.org>
Message-Id: <1254764158.9900.27.camel@dbooth-laptop>

> On Oct 4, 2009, at 12:35 PM, Paola Di Maio wrote:



> >  [ . . . ]  I am trying to match the UML and E/R view of the world
> > into RDF.

By far the biggest "gotcha" in coming from a UML, E/R, object-oriented,
or relational database perspective is that those technologies are based
on the closed world assumption (CWA), whereas semantic web technology is
based on the open world assumption (OWA):
http://en.wikipedia.org/wiki/Open_world_assumption

Actually it is a bit of a simplification to say that those technologies
use the CWA but semantic web technology uses the OWA, because you *can*
design systems based on the OWA using those technologies, and the CWA
can be used (very helpfully) in certain situations when using semantic
web technology.  But the orientation is different, and getting used to
it can take time.




-- 
David Booth, Ph.D.
Cleveland Clinic (contractor)

Opinions expressed herein are those of the author and do not necessarily
reflect those of Cleveland Clinic.
Received on Monday, 5 October 2009 17:36:29 UTC

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