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Patterns for representing mass-produced objects? (FRBR revisited)

From: Dan Brickley <danbri@danbri.org>
Date: Tue, 30 Sep 2008 15:12:58 +0200
Message-ID: <48E225DA.7060508@danbri.org>
To: public-owl-dev@w3.org
Cc: Alistair Miles <alistair.miles@zoo.ox.ac.uk>, Thomas Baker <tbaker@tbaker.de>

Hello, Ontology experts.

I'm looking for advice on current OWL-friendly best practices for 
modelling mass-produced items and their (possibly varying) 
characteristics. The motivation here is discussions during the Dublin 
Core conference last week, and from something in the Library and 
bibliographic metadata world called FRBR - the 'Functional Requirements 
for Bibliographic Records', http://en.wikipedia.org/wiki/FRBR

A FRBR-driven perspective is slowly getting traction in the library 
world, and is important also in discussions about the future directions 
for Dublin Core. FRBR attempts to give a better account of what kinds of 
things Libraries describe in their bibliographic records, such that we 
can better deal with the digital age (DVDs, "multimedia", translations, 
versions and editions etc.). FRBR conceptualises things in terms of 
'Works', "Expressions", "Manifestations" and eventually, countable 
"Items". See the Wikipedia reference above to track down full details.

There are efforts (notably by Ian Davis of Talis, see 
http://www.frbr.org/2005/10/03/ian-davis-frbr-in-rdf) to express these 
notions directly as RDF/OWL classes. The Library cataloguing standard 
AACR2 is currently being revised (by the Resource Description and Access 
group, see http://www.rdaonline.org/) and taking on board FRBR ideas.

I have long had a suspicion that some of the distinctions that FRBR make 
sare more general, and deal with issues that can have common class-based 
modelling idioms. Basically the problem of the library is that it needs 
to keep track of countable, locatable, damage-able items, as well as 
model their shared characteristics.

So a book's title, topic, authorship etc, expected number of pages, etc 
are attached at a different level of abstraction to information about 
its location, physical state, owner, actual number of pages, and so on.

One of the problems we've seen with FRBR deployment is that, because it 
has only these 4 "buckets" to put things in, some lack of agrement about 
whether something is a "Work" or an "Expression". The FRBROO project 
attempts to address this by combining it into the larger CIDOC CRM 
ontology, see http://en.wikipedia.org/wiki/FRBRoo . This is useful I 
think, but dauntingly large, and doesn't exploit the richness we have in 
OWL for describing the membership rules for classes.

So my thought here is that it is also worth considering an alternate 
model, in which "Work", "Expression", "Manifestation" and "Item" are 
thought of as functional requirements on our ontologising, rather than 
as directly modelled classes.

Hence my question here. How do ontologists lately tend to model things 
like an aircraft part, or other mass-produced item, when we have a 
situation in which (a) the design of these copied itself needs modeling 
(b) their instances may be flawed, damaged or lack adherance in various 
ways towards their stereotypical ideal.

I've been thinking that we could partially model this by some annotation 
on the class which pointed to a description of an indicative instance. 
For example, a T-Shirt design might typically be associated with T-Shirt 
instances that have a certain weight, colour, and so on. I don't want to 
make strong OWL claims that each actual shirt has just this weight, 
colour, ... any more than a library wants to imply that the actual 
number of pages in a shelved book is necessarily what we'd expect from 
the ideal.

Hope I'm making some sense here! I guess the issue I'm skirting around 
is how to handle default reasoning in RDFS/OWL, and whether there are 
deployed patterns that work for describing typical manufactured 
instances which might be re-usable in the bibliographic world.

Thanks for any thoughts / pointers.



ps. I made a couple of sketches in diagram / slide form, which might 
help indicate what I'm on about...

http://www.flickr.com/photos/danbri/2891150205/ (static class view)
http://www.flickr.com/photos/danbri/2892286406/in/photostream/ (timeline 
Received on Tuesday, 30 September 2008 13:13:39 UTC

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