MARC21 as RDF

Now that it’s there, what can we do with it?

ALA Dallas 1/20/12

Questions for TodayWhy did we decide to do this?How did we do it?What is this, really?What does this look like?Where do we go from here?

ALA Dallas 1/20/12

Why Did We Do This?We’re very interested in the problems

of mapping in the Semantic Web◦ See paper: http

://dcevents.dublincore.org/index.php/IntConf/dc-2011/paper/view/52

We wanted to explore these issues in the context of MARC21

Others doing maps had cherry-picked available properties—we wanted to do them all

ALA Dallas 1/20/12

How Did We Do It?OMR has lacked upload capability—

that was built for this purpose by Jon Phipps, OMR developer

Gordon Dunsire built all the spreadsheets in Google Docs, including the URI patterns

I did most of the testing and some of the error handling

Not rocket science, but a solid few weeks of work

ALA Dallas 1/20/12

What Is It Good For?It’s the beginning, not the ending …There’s more work to be done, but

we wanted people to be able to use it for experimentation right away

We included *almost* everything—over 10,600 properties and vocabulary concepts in all

It can be downloaded in pieces, we haven’t yet set up an ‘everything’ download capability (we will)

ALA Dallas 1/20/12

MARC21 in the Open Metadata RegistrySeparate RDF property available

◦For every attribute in the fixed-data fields Based on character position

◦For every combination of indicators and subfield codes within a tag Including non-filing indicators Some tags excluded (for now)

RDF/SKOS vocabularies (with definitions!) available for all code lists for the fixed-data fields

ALA Dallas 1/20/12

MARC21 in the Open Metadata RegistryThere’s a consistent pattern used

to coin marc21rdf.info URIs Designed to enable a

knowledgeable cataloger to ‘guess’ the correct URI…

ALA Dallas 1/20/12

MARC21 in the Open Metadata RegistryURIs for properties based on the

MARC21 encoding◦“M” + tag + indicator 1 + indicator 2

+ subfield code Underscore substituted for blank

E.g. M24011d◦Date of treaty signing in Uniform

Title, with 1 nonfiling character and intended to be printed or displayed

ALA Dallas 1/20/12

MARC21 in the Open Metadata RegistryURIs for concepts based on the

MARC21 codes◦E.g. a (code for playback speed of a

sound recording)◦16 rpm

Each vocabulary and concept has its own URI◦E.g. soundrecordingspd#◦E.g. soundrecordingspd#a (for 16

rpm)

ALA Dallas 1/20/12

MARC21 in the Open Metadata RegistryData from MARC21 legacy records can

be mechanically-mapped to the corresponding RDF properties at “Level 0”

Level 0 properties can be mapped to a series of more generic properties (Level 1 and above)◦To clarify and separate semantics from

syntax◦Relatively simple for fixed-data fields, but

significant issues to be tackled for variable tags.

ALA Dallas 1/20/12

MARC21 in the Open Metadata RegistryGeneric properties can be used to

map from MARC21 to other metadata schemas/formats◦Example goal: from MARC21 title (245

$a) to Dublin Core title, ISBD title proper, RDA manifestation title, etc.

MARC21 data can be retained in RDF without loss of semantics or values, and made interoperable with data from other sources via semantic relationships

ALA Dallas 1/20/12

RDF graph of 00X mapping pattern for an attribute with more than one valueand no significance in the order of values

ALA Dallas 1/20/12

Partial RDF graph of 00X mapping pattern for two or more attributes withmore than one value and significance in the order of values

ALA Dallas 1/20/12

RDF graph of 00X data from National Library of Scotland record for Legacy by Robert Buchanan

ALA Dallas 1/20/12

Partial RDF graph of 00X data from OCLC record for Abbey Road by the Beatles

ALA Dallas 1/20/12

http://marc21rdf.info

ALA Dallas 1/20/12

Property List: 1XX

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Property Detail: Relator codes

ALA Dallas 1/20/12

What’s Left To Do?Build on the ‘Level 0’

representations to better reflect the reality and complexity of MARC21

Continue to explore the usefulness of the process we used, and how it might be used for other element sets

Write it up for the benefit of othersNew DCMI Vocabulary Management

Community seems a good place for this activity

ALA Dallas 1/20/12

Questions?Contact for Diane:

metadata.maven@gmail.comContact for Gordon

gordon@gordondunsire.com◦(the middle section of slides were

his)

Please let us know what you think!