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Re: bnodes

From: Reto Bachmann-Gmür <rbg@talis.com>
Date: Thu, 04 Oct 2007 11:39:59 +0200
Message-ID: <4704B4EF.7020807@talis.com>
To: Sandro Hawke <sandro@w3.org>
CC: Bijan Parsia <bparsia@cs.man.ac.uk>, public-owl-dev@w3.org

Sandro Hawke wrote:
> =?UTF-8?B?UmV0byBCYWNobWFubi1HbcO8cg==?= <rbg@talis.com> writes:
>> Sandro Hawke wrote:
>>> ...
>>> It often seems to me that bnodes should have been left out of RDF.
>>> They're useful, but also painful.   (Or maybe, all things considered,
>>> RDF should have been left out of RDF.  :-)
>>>  =20
>> If we want to keep RDF but drop something, there's only named nodes we
>> can drop without loosing expressiveness. We would have to introduce an
>> inverse functional property pointing to a URI-Literal. This would also
>> make the owl:sameAs statement obsolete (it would just be one b-nodes
>> with multiple name-properties). Another advantage would be that there
>> are less arbitrary choices to take when describing a world with things
>> with multiple names, currently you can arbitrarily decide which
>> properties to associate with which of the same resources (the concept of
>> having multiple things being the same, seems counter-intuitive to me
>> anyway).
> Yes, indeed.    I proposed this about six years ago [1], but never got
> any traction with it.
> RDF has a clunky design.  Most elegent, I think, would be bnodes +
> strings + a uname property.  Another approach would be to get rid of
> bnodes (and, yes, sacrifice some functionality.)  But, anyway, this is
> water under the bridge.  (Still, it's useful to talk about sometimes, to
> at least acknowledge the issues, even if we can't fix them.  Otherwise
> people have a hard time learning it.)
Maybe the proposal to (re)introduce the '=' sign in turtle could be a
step in the right direction as it leads to see more clearly that the
name is very similar to a property and makes it more natural to add
multiple names.

[ = <http://eg.com/joe/>; = <http://eg.org/smith@me>;
                 foaf:name "Joe Smith" ].

The problem with named nodes is less a technical one than and more a
social/educational one as it makes resources with exactly one name
appear special and makes it harder to explain that resources can have 0
or any number of names.

>       -- Sandro
> [1] http://www.w3.org/2001/12/uname/ 

Reto Bachmann-Gmür
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Received on Thursday, 4 October 2007 09:40:12 UTC

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