- 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>
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