RELATORS, ROLES AND DATA… … similarities and differences

RELATORS, ROLES AND DATA…

… similarities and differences

Relators, Roles & Data 2

Linked Data is About Machines• Traditional cataloging considers identification via text

adequate (for physical things mostly)• A ‘record’ aggregates statements, but the identity of the resource

being described is often squishy (a title? Title plus author? ISBN?)• Digital identity must be significantly clearer (a URI/URL?) because

immediate access to the information behind the URI is expected to be available

• Our entry into the digital world is forcing us to look more carefully at our practices

• Within those practices, we need to identify what we can change now, and what should wait until later …

• In all cases, understanding what underlies the choices makes those choices clearer

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Model of ‘the World’ /XML

• XML assumes a 'closed' world (domain), usually defined by a schema:• "We know all of the data describing this resource. The single description must be a valid document according to our schema. The data must be valid.”

•XML's document model provides a neat equivalence to a metadata 'record’

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Model of ‘the World’ /RDF

• RDF assumes an 'open' world:• "There's an infinite amount of unknown data describing this resource yet to be discovered. It will come from an infinite number of providers. There will be an infinite number of descriptions. Those descriptions must be consistent."

•RDF's statement-oriented data model has no notion of 'record’ (rather, statements can be aggregated for a fuller description of a resource)

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General RDA Vocab Strategy

• The Semantic Web was the ‘mental model’• Made decisions that supported the creation of a “bridge”

between XML and RDF

• Vocabularies were built to allow easy extension• Used RDF Schema (RDFS), Simple Knowledge

Organisation System (SKOS) and Web Ontology Language (OWL)

• Decisions oriented to favor approaches that can be generalized to make other vocabulary based standards web-friendly, available for use in applications, and easily updated by communities

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Roles: Attributes or Properties?• In 2005, the DC Usage Board worked with LC to build a

formal representation of the MARC Relators so that these terms could be used with DC• This work provided a template for the registration of the

role terms in RDA (in Appendix I) and, by extension, the other RDA relationships

• Role and relationship properties in RDA are registered at the same level as elements, rather than as attributes (as MARC does with relators, and RDA does in its XML schemas)

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Relators, Roles & Data 7Sept. 7, 2012

Resource X hasAuthor [person URI]

RDF Triple

XML snippet

<!– frbr Work --> <frbr: C1001>

<role:author> <frbr:Person>

<nameOfThePerson> Vonnegut, Kurt

</nameOfThePerson> </frbr:Person>

</role:author></frbr Work>







How are these properties related?


*On the table …• Roles and relationships as properties should be usable in

XML as well as RDF • In XML the usual practice is to repeat the structure of the

vocabulary term in each instance – not necessary in this case, when the structure is carried in the property declaration

• If separate attribute vocabularies for roles and vocabularies is really desired, they can be added to the set• This strategy would allow the full role vocabulary (all 250 roles) to

be available for use as XML attributes• Discussions ongoing with JSC to consider this option

Sept. 7, 2012


Issues Around Extension & Mapping• Should there be a formal process established?

• If yes, who should establish it? The JSC? Should it look like the current JSC and CC:DA processes for revising the rules?

• If no, are we prepared for something a bit more informal, and perhaps a bit more chaotic (but perhaps with quicker results)?

• More informal processes could include:• Allowing the use of ‘local’ extensions by catalogers, with

expectation of formal inclusion at a later time• Crowdsourcing, using wikis, existing discussion lists, other similar

tools?• Building maps between other specialized vocabularies and ours,

and thus using other vocabularies more routinely?

• Some combination of the above?

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RDA:adaptedAs

RDA:adaptedAsARadioScript

hasSubproperty

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RDA:adaptedAs


KidLit:adaptedAsAPictureBook

hasSubproperty

hasSubproperty

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Extension using Generalized Properties


RDA:adaptedAs


KidLit:adaptedAsAPictureBook

hasSubproperty

hasSubpropertyKidLit:adaptedAsAChapterBook

hasSubpropert

y

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Extension using Generalized Properties


Extending Vocabularies ‘on-the-go’


Concept Vocabulary Relationships


Mapping• Building relationships between vocabularies is not

necessarily a proprietary activity or tied to particular applications (not ‘crosswalking’ as we have understood that term)

• http://MARC21rdf.info provides a beginning point for mapping library data that is easily shared and modified to meet a variety of needs

• New approaches go beyond ‘sameAs’ and suggest the potential for more granular, nuanced relationships

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http://MARC21rdf.info/


Links and Contact Info

RDA Vocabularies: http://rdvocab.info

MARC 21 in RDF: http://MARC21rdf.info

Diane: [email protected]

“RDA Vocabularies: Process, Outcome, Use”, DLib Magazine, Jan./Feb. 2010: http://dlib.org/dlib/january10/hillmann/01hillmann.html

Sept. 7, 2012

http://rdvocab.info/

http://MARC21rdf.info/

mailto:[email protected]

http://dlib.org/dlib/january10/hillmann/01hillmann.html

http://dlib.org/dlib/january10/hillmann/01hillmann.html

Documents

RELATORS, ROLES AND DATA… … similarities and differences