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

Re: Disjointedness of FRBR classes

From: Karen Coyle <kcoyle@kcoyle.net>
Date: Wed, 26 Oct 2011 12:12:13 -0700
Message-ID: <20111026121213.42333qp0zd6gjrt9@kcoyle.net>
To: Tom Baker <tbaker@tbaker.de>
Cc: public-lld@w3.org
Tom and Gordon,

Given the strict nature of the FRBRer declaration, I wonder if this  
couldn't be included in the discussion of Application Profiles to see  
if a solution might be found there. There could be a general set of  
FRBR classes and properties that have few constraints, then the  
library community could have an AP that performs the functions of  
FRBRer. (Perhaps FRBRer *is* that AP.) An AP makes sense to me because  
of the obvious desire to model enforceable constraints in an  
application.

The big trick, then, becomes creating a model that would allow you to  
intermingle bibliographic metadata that follows different APs of FRBR,  
as well as those that do not follow FRBR at all. I can imagine class  
and sub-class relationships that facilitate this, yet even the loosest  
version of FRBR would need to have a usable relationship to  
undifferentiated (no WEMI) bibliographic descriptions, and that's the  
one that still won't come clear for me.

Meanwhile, I think that Tom is right in that this "instance" of FRBR  
is designed for a situation with trained catalogers, as well as  
applications that enforce the constraints. It defines a closed world.  
(I'm less sure that the Tillett/Murray definition is more open, but I  
would like it to be.) The AP model might be able to create a more open  
world for it be part of.

kc

Quoting Tom Baker <tbaker@tbaker.de>:

> On Wed, Oct 26, 2011 at 04:03:20PM +0100, Gordon Dunsire wrote:
>> > property "is realizer (corporate body) of" is disjoint with properties:
>> > - has name of the corporate body
>> > - has number associated with the corporate body
>> > - has place associated with the corporate body
>> > - has date associated with the corporate body
>> > - has other designation associated with the corporate body
>
> Okay, so we have [1]:
>
>     <frbrer:P2012> <rdfs:label> "is realizer (corporate body) of"@en .
>     <frbrer:P2012> <rdfs:range> <frbrer:C1002> .
>     <frbrer:P2012> <rdf:type> <owl:ObjectProperty> .
>     <frbrer:P2012> <rdf:type> <owl:NamedIndividual> .
>     <frbrer:C1002> <rdfs:label> "Expression"@en .
>     <frbrer:C1002> <rdf:type> <owl:Class> .
>     <frbrer:C1002> <rdf:type> <owl:NamedIndividual> .
>     <frbrer:P2012> <rdfs:domain> <frbrer:C1006> .
>     <frbrer:C1006> <rdfs:label> "Corporate Body"@en .
>     <frbrer:C1006> <rdf:type> <owl:Class> .
>     <frbrer:C1006> <rdf:type> <owl:NamedIndividual> .
>     <frbrer:P2012> <owl:propertyDisjointWith> <frbrer:P3045> .
>     <frbrer:P3045> <rdfs:label> "has place associated with the  
> corporate body"@en .
>     <frbrer:P3045> <rdfs:domain> <frbrer:C1006> .
>     <frbrer:P3045> <rdf:type> <owl:NamedIndividual> .
>
> and then:
>
>     <frbrer:P2012> <owl:propertyDisjointWith> <frbrer:P3045> .
>
> I'm struggling to see the interoperability gains of putting all  
> these "disjoint
> property" statements into the definitions of the base vocabulary.  Triples
> about disjointness are 45% of the 3930 triples in [1].
>
>> Property disjointness is given where the value of the object of an instance
>> triple should not be interpreted as referencing the same thing as for an
>> instance triple using a different property but with the same subject.
>
> As OWL2 puts it: "two properties are disjoint if there are no two individuals
> that are interlinked by both properties" [2].  I can understand why one would
> want to apply such precise semantics in controlled environments (e.g., a
> cataloging department) for the purposes of controlling the quality of data
> produced, but I do not see the benefit of imposing such strong  
> semantics on the
> rest of the world by including them in the very definitions of properties and
> classes.
>
> To my way of thinking, the presence of these strong semantics seems  
> to tell the
> world that nobody should even _think_ of using these vocabularies unless they
> really really know, understand, and subscribe to the precise interpretation
> encoded therein and are confident they can apply it correctly (and that
> speakers of Chinese, Spanish, and Arabic should hope the translations are
> good).  The semantically strong definition seems to imply that these
> vocabularies are really only intended for use by trained, professional,
> English-speaking library catalogers using OWL reasoners, and that  
> nobody should
> even think of building on FRBR with additional properties without  
> defining them
> with the same high degree of precision.
>
> If so, that feels like a missed opportunity, because FRBR is potentially very
> useful outside of that relatively small world.  Defining FRBRer without all
> this disjointness, on the other hand, would not at all preclude the  
> application
> of strong interpretations when really needed in specific contexts, such as
> controlling the output of cataloging departments.
>
> In the end, though, I wonder if this strong disjointness is really  
> supported by
> the FRBR model itself [3]?   For example, I read:
>
>     "On a pragmatic level, defining work as an entity in the model serves a
>     number of purposes. It enables us to give a name and draw  
> relationships to
>     the abstract intellectual or artistic creation that encompasses all the
>     individual expressions of that work. ....  It is the entity defined as
>     work, therefore, that provides us with this grouping capability. ... On a
>     practical level, the degree to which bibliographic distinctions are made
>     between variant expressions of a work will depend to some extent on the
>     nature of the work itself, and on the anticipated needs of users and on
>     what the cataloguer can reasonably be expected to recognize from the
>     manifestation being described."
>
> In such places, the language of FRBR seems to suggest less a rigid  
> ontology of
> the world "as it is" and more a set of distinctions that have value because
> they are useful in a pragmatic sense, e.g., in splitting parts of a  
> description
> into separate bundles that can be maintained and referenced in a more
> distributed manner.  As Barbara Tillett and Ron Murray put it [4]:
>
>     E-R and OO modeling may be used effectively to create information systems
>     based on an inventory of "things of interest" and the relationships that
>     exist among them. Unfortunately, the things of interest in Cultural
>     Heritage institutions keep changing and may require redefinition,
>     aggregation, disaggregation, and re-aggregation. E-R and OO modeling as
>     usually practiced are not designed to manage the degree and kind  
> of changes
>     that take place under those circumstances.
>
> Their reference to WEMI entities as "sub-graphs" which "reproduce  
> bibliographic
> characteristics found useful by catalogers, scholars, other educationally
> oriented end-users, and to varying extents the public in general" -- as
> "views", or as "groups of statements that occupy different levels of
> abstraction" -- suggests a more flexible (and useful) basis for a formal
> expression of FRBR defined, perhaps, more along the lines of minimal semantic
> commitment.
>
> Tom
>
> [1]  
> http://triplr.org/ntriples/iflastandards.info/ns/fr/frbr/frbrer/frbrer.rdf
> [2]  
> http://www.w3.org/TR/2009/REC-owl2-primer-20091027/#a_DisjointObjectProperties
> [3]  
> http://www.ifla.org/publications/functional-requirements-for-bibliographic-records
> [4] http://www.ala.org/ala/mgrps/divs/lita/publications/ital/prepub/index.cfm
>
> --
> Tom Baker <tom@tombaker.org>
>



-- 
Karen Coyle
kcoyle@kcoyle.net http://kcoyle.net
ph: 1-510-540-7596
m: 1-510-435-8234
skype: kcoylenet
Received on Wednesday, 26 October 2011 19:12:45 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Wednesday, 26 October 2011 19:12:46 GMT