Evolving MARC 21 for the future

Rebecca GuentherCCS Forum, ALA Annual

July 10, 2009

Overview of presentation

The current MARC environment Successes of MARC Moving to XML RDA and FRBR experimentation Linked data Issues to resolve

Credits

Sally McCallum for some slide content

John Espley for FRBR implementation

Clay Redding for Linked Data content

What is MARC 21?

A syntax defined by an international standard for communications with 2 expressions: Classic MARC (MARC 2709) MARCXML

A data element set defined by content designation and semantics

Institutions do not store “MARC 21”, as it is a communications format

Many data elements are defined by external content rules; a common misperception is that it is tied to AACR2

A set of 5 formats for different purposes: Bibliographic, Authority, Holdings, Classification, Community Information

The current MARC environment

Billions of rich descriptive records in MARC systems

Many national formats have been harmonized with MARC 21

Integrated library systems that support MARC bibliographic, authority and holdings format for different functions

Wide sharing of records for 30+ years OCLC is a major source of records MARC records are being reused (sometimes

converted) and repackaged

MARC successes

Can carry data formulated by different cataloging rules and conventions Multiple descriptive rules, different principles and

models Different subject thesauri Multiple languages and scripts

Cooperation in record exchange has resulted in widespread use and cost savings

Richness of MARC records supports multifaceted retrieval Coded data Parsed data

Problems with MARC

MARC 2709 syntax problems Limitation of available fields, subfields,

indicator values, etc. Redundant data (fixed vs. variable fields) Controlled values embedded in the

standard Ability to link Limits to extensibility Lack of explicit hierarchical levels

Some progress…

MARCXML Definition of $u, $w and $0 for

linking Definition of $2 to specify source of

controlled values Exploration into use of URIs MODS

Streamlining MARC 21 into the future

Take advantage of XML Increasingly use MARC 21 in an XML structure Take advantage of freely available XML tools

Develop simpler (but compatible) alternatives MODS

Allow for interoperability with different XML metadata schemas Assemble coordinated set of tools

Provide continuity with current data Provide flexible transition options

MARCXML

MARCXML uses the MARC data element set in an XML syntax

Lossless roundtrip conversions Simple flexible XML schema, no need to

change when MARC 21 changes Interoperability with different XML schemes by

taking advantage of free XML tools Collaborative use of metadata for access

(e.g.OAI) Continuity with current data and flexible

transition options

Example: http://lccn.loc.gov/2004012412

MARC 21 evolution to XML

More use of MARCXML

Transition to exchange in MARCXML instead of MARC 2709

Take advantage of namespaces to allow for extensions (e.g. technical metadata)

Potential to extend with new attributes or subfield markers

Other related XML schemas: MODS

Eliminates some of the problems with MARC (e.g. lack of tags/subfield codes)

More user-friendly (uses language tags) Repackages redundant data elements into one Can carry hierarchical data Less tied to cataloging rules Highly compatible with MARC but simpler,

although retaining some richness Widely implemented especially for digital

projects Governed by Editorial Committee

Example: http://lccn.loc.gov/2004012412/mods

Other related XML schemas: METS

METS A container/information package Wrapper for MARCXML and MODS descriptions Allows for additional technical and

preservation metadata Enables tracking of actions on the metadata

itself LC is exploring a native XML database for search

and retrieval bringing together records from many internal systems using MODS/MARCXML/METS

Experimentation with RDA, FRBR and RDF

MARC changes to accommodate RDA MODS changes to accommodate RDA FRBR experimentation

VTLS has implemented a FRBR based system using MARC

Other systems are looking at migrating to reflect entity-relationship models

Semantic web experiments Modeling MODS and MADS as RDF Modeling MARC as RDF See Martha Yee’s article in Information Technoclogy

and Libraries (v. 28, no. 2, June 2009)

Example of FRBR implementation of MARC: VTLS

Single database can have FRBR and non-FRBR records

System is “aware” of FRBR record level and changes displays as needed

Display of FRBR records are in tree structure

Local level fields have values of W, E, and M to indicate type of FRBR record

001 and 004 used as linking tags

Experimentation with “Linked data”

Library of Congress Authorities & Vocabularies service: http://id.loc.gov

Allows both human-oriented and programmatic access to LC-promulgated authorities and vocabularies

Actionable URIs associated with concepts First offering is Library of Congress Subject Headings, but

more to come: e.g. Thesaurus of Graphic Materials, ISO 639-2, MARC code lists, etc

Advantages Facilitate development and maintenance process for

vocabularies Expose vocabularies to wider communities Offer bulk downloads

Example:http://id.loc.gov/authorities/sh85049843

Issues to resolve for bibliographic formats

Actionable vs. descriptive Parsed vs. text Controlled/access vs. transcribed Codes vs. words Library vs. non-library traditions My model vs. your model Stability vs. change Basic retrieval vs. scholar retrieval Cost of change

How do we move forward? Continue RDA/FRBR implementation changes Transition to XML for exchange (syntax) Evolve MARC 21 (data element set)

Analyze successes that need to be carried over into a streamlined MARC

Consider MODS features to be incorporated Consider use of MARC 21 for different cataloging

rules, models and traditions, not just RDA Consider cost implications Assure continuity with current data Evolution will take some time and will be in

phases

Comments?

Tell us what you think: ndmso@loc.govor rgue@loc.gov