W3C home > Mailing lists > Public > public-lld@w3.org > October 2011

Re: Disjointedness of FRBR classes

From: Tom Baker <tbaker@tbaker.de>
Date: Mon, 24 Oct 2011 13:19:52 -0400
To: Ross Singer <ross.singer@talis.com>
Cc: Tom Baker <tbaker@tbaker.de>, Karen Coyle <kcoyle@kcoyle.net>, public-lld@w3.org
Message-ID: <20111024171951.GA43074@julius>
On Mon, Oct 24, 2011 at 04:48:41PM +0100, Ross Singer wrote:
> > Please remind me who exactly is saying that the WEMI classes are formally
> > disjoint.  There are several formalized expressions of FRBR in circulation.
> > Which one(s) do you mean here and what is the status of that expression
> > according to IFLA (or JSC, or anyone else)?  I was under the impression that
> > the RDF expressions were all still just drafts, hence subject to possible
> > revision...
> Tom, this is a fair question, so I just revisited:
> Ian Davis' "original" FRBR vocabulary is formally constrained (see:
> http://vocab.org/frbr/core.rdf)
> RDA's has no formal constraints whatsoever (so a resource could be a
> Person, Subject, Place, Work and Item):
> http://rdvocab.info/uri/schema/FRBRentitiesRDA.rdf
> FRBRer (IFLA FRBR) also (despite our long debate on this list) has no
> formal constraints on any of the Group 1,2 or 3 classes
> (http://metadataregistry.org/schemaprop/list/schema_id/5.html).

Thank you for this clarification!  

(As an aside: does anyone know if there is a citable RDF dump of FRBRer for
those of us who prefer to get vocabularies directly in RDF instead of having to
find one's way around Web pages? It seems inefficient, in this context, to cite
a vocabulary with a URL that calls a database that generates HTML pages that
can be navigated to get to RDF representations, but of unknown status.  For
example, by clicking around, I find [1], but this looks like a database call to
potentially mutable contents and, like FRBRentitiesRDA.rdf, appears to contain
no indication of date or version. If formal constraints were added to the
FRBRer vocabulary tomorrow, how would I cite this "unconstrained" version?)

[1] http://metadataregistry.org/schema/show/id/5.rdf

> So I stand corrected (and here we can dust off that old chestnut about
> the word "assume").  There is nothing logically wrong with with saying
> that a resource is both a frbr:Expression and a frbr:Manifestation.

Great - that sounds right to me...

> I cannot say that I feel that this is necessarily "right", though.
> Something seems ontologically wrong with the complete absence of
> constraints.

Suppose that according to Source A, Resource X is a frbr:Expression, and
according to Source B it is a frbr:Manifestation.  And suppose you wanted to
enforce a strict interpretation of FRBR, e.g., for quality control in a
cataloging department.  Could one not easily define rules to treat the
statements from Source A and Source B as a contradiction and make the computer
beep and flash red lights when such a discrepancy is detected?  If so, what
would be the additional requirement for imposing such a strict interpretation
on _all_ downstream users and consumers of the vocabulary by declaring the
classes to be disjoint (which, I am happy to hear, has not been done)?


Tom Baker <tom@tombaker.org>
Received on Monday, 24 October 2011 17:20:50 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 20:27:44 UTC