On 3/30/15 12:46 PM, Karen Coyle wrote:
[log in to unmask]" type="cite">Of
course, applications do need to impose constraints on data. But
having those constraints bundled with the meaning of the data
elements greatly limits the flexibility of the metadata language.
DC therefore has defined an "application profile" that is where
the application-specific constraints (mandatory, repeatable) are
defined. So you have maximum interoperability built into the
definition of your metadata terms, and you still have the ability
to customize the metadata "record" for your particular needs using
an application profile.
Something else occurred to me after writing this, and it may not be
obvious to others...
There is a significant difference between what the BIBFRAME
vocabulary defines and the output from BIBFRAME programs. Because
BIBFRAME is an RDF/OWL vocabulary, and because it does not define
classes as disjoint, both of these are "valid" bibliographic
statements based on the BIBFRAME vocabulary:
1.
ex:ResourceA
bf:workTitle ex:AdventuresOfTomSawyer ;
bf:hasInstance ex:ResourceB ;
bf:creator lcna: n79021164 ;
bf:language iso639-2:eng .
ex:ResourceB
bf:providerDate "1996" ;
bf:instanceOf ex:ResourceA ;
bf:instanceTitle ex:TheAdventuresOfTomSawyer .
2.
ex:ResourceC
bf:creator lcna: n79021164 ;
bf:workTitle ex:AdventuresOfTomSawyer> ;
bf:language iso639-2:eng ;
bf:instanceTitle ex:TheAdventuresOfTomSawyer> ;
bf:providerDate "1996" .
In other words, the vocabulary does not determine that you must have
a work "thing" and an instance "thing." It also does not have any
say on whether properties are mandatory or repeatable. There is
nothing in the vocabulary that would prevent you from having no work
title, or a dozen work titles. This is inherent in RDF/OWL, which
cannot enforce rules over a vocabulary, by its nature. Conversion of
MARC records of course turns out bibliographic data consistent with
what is in the MARC records (e.g. one 245). But the separation of
properties into work and instance is a decision being made in the
conversion programs. This means that there are rules being applied
in the programs that process BIBFRAME records, but these rules are
in addition to the BIBFRAME vocabulary, not part of it.
I don't recall any discussion of the rules that will be used in LC's
implementation of the BIBFRAME vocabulary, but should this data
become available on the open Web, only the essence of the vocabulary
as defined in RDF/OWL will be applicable. It would be helpful to
have clarity on the differences between the vocabulary and the
implementation.
kc
--
Karen Coyle
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