W3C home > Mailing lists > Public > www-rdf-interest@w3.org > May 2002

Re: bNodes wanted

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Sat, 25 May 2002 10:28:41 -0400
To: danbri@w3.org
Cc: sandro@w3.org, www-rdf-interest@w3.org
Message-Id: <20020525102841L.pfps@research.bell-labs.com>
From: Dan Brickley <danbri@w3.org>
Subject: Re: bNodes wanted 
Date: Sat, 25 May 2002 06:09:29 -0400 (EDT)

> On Fri, 24 May 2002, Peter F. Patel-Schneider wrote:
> 
> > > It seems like the question is whether I can properly generate a Skolem
> > > constant.  There are several ways to generate URIs that no one else
> > > will ever generate; you can pick one that meets your needs:
> > >
> > >     - the tag: URI algorithm for human-readable ones [1]
> > >     - the UUID algorithm for easy machine generation
> > >     - a cryptographicaly secure random number if you're
> > >       seriously concerned about duplicate generation
> > >       (such as by malicious 3rd parties)
> >
> > None of these work.  As soon as any other agent sees the skolem URIrefs
> > then it can use the URIrefs, resulting in them possibly being used in other
> > doucuments.
> 
> Hey we agree on something :) Absolutely right.
> 
> 
> > > If you also want to make sure no one can use it after the fact, then
> > > you certainly need bNodes.  But I don't know why you'd want that.  Use
> > > cases?
> >
> > Lets see:
> >
> > 1/ containers that cannot be added to by other parties
> > 2/ resources that cannot be referred to by name, only in terms of their
> > relationships to other resources
> 
> I guess for 1/, you'd need to be careful not to describe your container
> with enough information (such as a daml:UnambiguousProperty, in the
> simplest case) to allow others to easily say things about it afterwards.
> I'm not sure that's always achievable. You might have some container and
> not want anyone to talk about it afterwards; yet others might start
> describing it (in RDF+WebOnt/etc) as 'the rdf:Seq that Peter mentioned in
> his message of 2002-05-25'. I don't think this can be avoided. Instead,
> we'd want strategies to avoid believing things claimed in such a matter,
> perhaps?

Well, RDF has no mechanisms for creating statements in one RDF graph use a bnode
from another RDF, so even being able to talk about the container, does not
allow one to, for example, add new elements to it.

> Dan

Peter F. Patel-Schneider
Received on Saturday, 25 May 2002 10:40:03 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:51:54 GMT