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RE: lcsh.info RDFa SKOS and content negotiation - use of RDF-style # IDs in RDFa?

From: Williams, Stuart (HP Labs, Bristol) <skw@hp.com>
Date: Fri, 3 Oct 2008 14:05:02 +0000
To: Steven Pemberton <steven.pemberton@cwi.nl>, Dan Brickley <danbri@danbri.org>, RDFa <public-rdf-in-xhtml-tf@w3.org>, "www-tag@w3.org WG" <www-tag@w3.org>
CC: Ed Summers <ehs@pobox.com>
Message-ID: <233101CD2D78D64E8C6691E90030E5C81B6CFA85CD@GVW1120EXC.americas.hpqcorp.net>

Hello Steven,

> I'm inclined to say "Well, of course", and I have to admit I
> still don't see the problem.

Dan's question roughtly was, "Is this an Ok way to name the concept?" with an implicit.. so that we can call it by the same name.

Your response was roughly, "...make the concept a blank node." ie. assert its existence, but don't give it a (global) name (which Pat Hayes also called you on).

How does not giving the concept a name solve Dan's problem?

Stuart
--
Hewlett-Packard Limited registered Office: Cain Road, Bracknell, Berks RG12 1HN
Registered No: 690597 England



> -----Original Message-----
> From: Steven Pemberton [mailto:steven.pemberton@cwi.nl]
> Sent: 03 October 2008 14:47
> To: Williams, Stuart (HP Labs, Bristol); Dan Brickley; RDFa;
> www-tag@w3.org WG
> Cc: Ed Summers
> Subject: Re: lcsh.info RDFa SKOS and content negotiation -
> use of RDF-style # IDs in RDFa?
>
> On Tue, 30 Sep 2008 18:16:34 +0200, Williams, Stuart (HP
> Labs, Bristol)
> <skw@hp.com> wrote:
>
> > Only parially. *iff* the primary topic node were not blank, but a
> > definite URI node, then merging would world provided that equivalent
> > nodes were involved.
> >
> > However, the identity of blank nodes is scoped only to the
> graph that
> > they are in. If you have the two graphs:
> >
> > {
> > _:StevenPemberton foaf:isPrimaryTopicOf
> <http://www.cwi.nl/~steven/> .
> > }
> >
> > {
> > _:StevenPemberton foaf:isPrimaryTopicOf
> > <http://www.w3.org/People/all#steven> .
> > }
> >
> > You cannot determine that they both named resources have the same
> > primary topic - so the blank topic node in this case is basically
> > useless establishing that what we have are different
> accounts of Steven
> > Pemberton.
> >
> > IIUC isPrimaryTopicOf is intended to establish the use of say
> > http://www.cwi.nl/~steven/ as a subject indicator for Steven Pemberton.
> > As a subject indicator the resource can only be a subject
> indicator for
> > one thing (hence inverse functional) - though there may be
> many subject
> > indicators for a given thing. So if we have the merged graph:
> >
> > {
> >         ex1:StevenPemberton foaf:isPrimaryTopicOf
> > <http://www.cwi.nl/~steven/>,
> <http://www.w3.org/People/all#steven> .
> >         ex2:StevenPemberton foaf:isPrimaryTopicOf
> > <http://www.w3.org/People/all#steven> .
> > }
> >
> > We can deduce that ex2:StevenPemberton is owl:sameIndividualAs
> > ex1:StevenPemberton (might be owl:sameAs) from the inverse
> functional
> > nature of isPrimaryTopicOf.
>
> I'm inclined to say "Well, of course", and I have to admit I
> still don't see the problem.
>
> There are things in the world without URIs (or with URIs that I don't
> know).
>
> I see the use of blanknodes in this way as an existential quantifier
> "There is a thing that...". Then of course if I say "there is
> a thing that
> is the principle topic of A" and "there is a thing that is
> the principle
> topic of B" they are not the same thing until I prove they are.
>
> But if I say, in two different graphs "there is a thing that is the
> principle topic of A", then those two things are clearly the
> same, and so
> everything I say about that thing in the two graphs can be
> merged. It all
> depends how you ground your blank nodes really.
>
> Best wishes,
> Steven
>
Received on Friday, 3 October 2008 14:07:36 GMT

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