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Re: Disjointedness of FRBR classes

From: Simon Spero <ses@unc.edu>
Date: Wed, 26 Oct 2011 18:12:48 -0400
Message-ID: <CADE8KM6rsjB+6u2Qs4XwMQO4KJK+SpniZ=T2LT-h_qWVrU9WMQ@mail.gmail.com>
To: Ross Singer <ross.singer@talis.com>
Cc: Tom Baker <tbaker@tbaker.de>, public-lld@w3.org, Karen Coyle <kcoyle@kcoyle.net>
Ross makes some good points here, though some of the statements that he
makes imply positions that are more constrained than I think he actually
holds.

The word "book" is a traditional example of a word that has multiple
meanings. Consider the following pair:

1) Did I lend you Moby Dick? Yes- the book is in my backpack.

2) Did you read Moby Dick? Yes- the book is deeply moving.

In (1) the word book refers to a tangible physical thing existing in
time-and-space.

In (2) the word book refers to  an intangible thing; there need be no
physical copies in existence to preserve the existence of this intangible
book; for example, if all physical copies were destroyed by Firemen, but the
contents were memorized and passed on through oral tradition, the book as
conceptual work remains.

The whole point of the model that FRBR is based on is to  carefully separate
these meanings. There are confusions in the ifla text, but the underlying
distinctions between the kinds of entities are important and have real
implications.

It is possible to construct variants of FRBR where work and item need not be
individuals- one approach is to retreat from absolute identity and use some
form of sortal relative identity; this is a useful way of viewing frbr from
the bottom up (imew); for example, when looking at version control systems
like svn.

Simon
On Oct 26, 2011 4:31 PM, "Ross Singer" <ross.singer@talis.com> wrote:

> On Wed, Oct 26, 2011 at 9:10 PM, Tom Baker <tbaker@tbaker.de> wrote:
>
> > Would it help simply to stop saying that the WEMI classes are disjoint?
>
> What's the benefit in this?  What have I said if I say that this thing
> is a Work and an Expression (since neither of these exist in nature)?
>
> If I am talking about a Book, I'm talking about a Book, not an
> Expression or Manifestation (although those concepts may be abstractly
> part of what is a Book).
>
> If anything, removing the restrictions seems to dilute the point of
> bothering with FRBR at all.
>
> -Ross.
>
> > Stating that Resource X is a Work and then stating that Resource X is an
> > Expression would be semantically acceptable.  A Work description could
> > potentially be seen as a Work "view" of Resource X while an Expression
> > description could -- without formal contradiction -- been seen as an
> Expression
> > "view" of the same Resource X.  What would break?  W, E, M, and I
> descriptions
> > could still be exposed as separate graphs, so the distributed management
> of
> > resource description -- drawing on bits from here and there -- would
> still be
> > supported.  In other words, one would not need to sacrifice the practical
> > benefits of FRBR.
> >
> > For this to work would of course require consistent data, but this could
> be
> > achieved by using the strong OWL ontology or the Application Profile, as
> > needed, when the data is created.
> >
> > The _formal-semantic_ barriers to merging WEMI data with legacy data
> (with WEMI
> > entities smushed into a single undifferentiated block) -- or with data
> that
> > simply slices up the world differently -- would simply melt away.  It
> would
> > come down to the classic, and unavoidable, judgement calls about how to
> > interpret data from a diversity of sources and perspectives.
> >
> > Tom
> >
> >> 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
> >
> > --
> > Tom Baker <tom@tombaker.org>
> >
> >
>
>
Received on Wednesday, 26 October 2011 22:13:19 GMT

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