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Re: Well Behaved RDF - Taming Blank Nodes, etc.

From: David Booth <david@dbooth.org>
Date: Thu, 13 Dec 2012 12:27:38 -0500
To: Bernard Vatant <bernard.vatant@mondeca.com>
Cc: Pat Hayes <phayes@ihmc.us>, semantic-web <semantic-web@w3.org>
Message-ID: <1355419658.2301.21502.camel@dbooth-laptop>
hi Bernard,

On Thu, 2012-12-13 at 10:48 +0100, Bernard Vatant wrote:
> Dear all
> 
> I'm 100% with Pat here in the defence of blank nodes, as ever [1]
> The more I'm using RDF daily, the more I love them, and seems to me
> you miss a lot of RDF expressivity by wanting everything to be
> uniquely identified by a URI
> Just another example : "John met a girl yesterday in a cafe". 
> Are you going to coin a URI for those ill-identified girl, cafe, and
> event? Certainly not. But you want to record this information in
> John's bio because you guess it's likely to be of some importance
> later in his life, even if so far you don't know more about it.
> 
> The "natural" expression of things in RDF is that some event in the
> life of John took place yesterday, involving some girl in some cafe. 
> 
> @prefix bio:<http://vocab.org/bio/0.1/>
> @prefix foaf:<http://xmlns.com/foaf/0.1/>
> @prefix schema:<http://schema.org/>
> 
> :John    bio:event   _:someEvent .
> _:someEvent  bio:Date  '2012-12-12' .
> _:someEvent  bio:Participant  _:someGirl .
> _:someEvent  bio:place _:someCafe .
> _:someGirl  a  foaf:Person .
> _:someGirl  foaf:gender  'female' .
> _:someCafe  a  schema:CafeOrCoffeeShop .
> 
Well Behaved RDF does not prohibit blank nodes, it just constrains their
use to avoid problems.  The example above *is* Well Behaved RDF.  It
could have been written in Turtle using only implicit blank nodes:

:John
    bio:event [
        bio:Date "2012-12-12" ;
        bio:Participant [
            a foaf:Person ;
            foaf:gender "female"
        ] ;
        bio:place [
            a schema:CafeOrCoffeeShop
        ]
    ] .


-- 
David Booth, Ph.D.
http://dbooth.org/

Opinions expressed herein are those of the author and do not necessarily
reflect those of his employer.
Received on Thursday, 13 December 2012 17:28:08 UTC

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