The Metadata Object Description Schema MODS

1
The Metadata Object Description Schema (MODS)

• D.C. Special Library Association
• Feb, 4, 2003
• Rebecca Guenther,
• Library of Congress

2
Overview of presentation

• Types of metadata
• Metadata Object Description Schema (MODS)
• Purpose
• Features
• Comparison with Dublin Core
• Implementation at LC

3
Types of Metadata

• Descriptive metadata
• Major focus of library catalog (especially MARC)
• Increased number of descriptive metadata
  standards for different needs
• Most standardized of type of metadata
• Administrative metadata
• Structural metadata
• Rights metadata
• Preservation metadata elements

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Descriptive metadata standards

• MARC
• MODS
• Dublin Core
• ONIX
• EAD

• VRD Core Categories
• CDWA
• TEI
• FGDC
• GILS
• MPEG-7

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How might descriptive metadata interact?

• MARC continues for exchange, perhaps in XML
• Libraries may receive records using other
  metadata schemes
• Descriptive metadata may come as part of digital
  objects
• Collaborative use of metadata for access
• OAI harvesting
• Z39.50 and ZING
• Reuse of existing elements/standards by different
  metadata schemes

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What is MODS?

• Metadata Object Description Schema
• Bibliographic element set (descriptive metadata)
• Initiative of Network Development and MARC
  Standards Office at LC
• Uses XML Schema
• Specifically for library applications, although
  could be used more widely
• A derivative of MARC

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How does MODS relate to MARC?

• Part of the MARCXML toolkit
• A MARC derivative
• Inherits MARC semantics
• Includes equivalent fields, but only a subset of
  all MARC fields
• Repackages some information
• More user-friendly

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Why MODS?

• XML (Extensible Markup Language) is the markup
  for the Web
• Investigating XML as a new syntax for MARC
  element set
• MARC XML architecture will accommodate various
  needs
• Allows conversions between syntaxes/schemas
• Need for rich descriptive metadata in XML but
  simpler than full MARC

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Potential uses of MODS

• As a Z39.50 Next Generation specified format
• As an extension schema to METS (Metadata Encoding
  and Transmission Standard) for descriptive
  metadata
• As an alternative format to represent metadata
  for harvesting (OAI)
• For original resource description in XML syntax
• For metadata in XML that may be packaged with an
  electronic resource

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Advantages of MODS

• Element set is richer than Dublin Core
• Hierarchy allows for description of complex
  digital objects
• Element set is more compatible with library data
  than ONIX or DC
• Element set is simpler than the full MARC format
  (MARCXML is entire format in XML syntax)

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Features of MODS

• Some data has been repackaged in some cases what
  is in several data elements in MARC may be
  brought together into one in MODS
• MODS does not assume the use of any specific
  cataloging code
• Reuse element descriptions throughout the schema
• Uses language-based tags
• Not intended to be a MARC replacement!

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Limitations of MODS

• Because its a subset of MARC fields, a
  conversion retains core data and loses other data
• Does not allow for a round-trip mapping to and
  from MARC
• Content rules are not covered by MODS, although
  definitions of elements come from MARC

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MODS for electronic resources

• Development
• electronic resources an important target
• input from several digital library projects
• Xlink attribute throughout
• Related item structure supports hierarchy needed
  for complex digital objects
• Digital origin attribute
• Several date types specifically for digital
  projects (e.g., capture)
• E-resource identifiers, e.g., DOI

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MODS high-level elements

• Title Info (mandatory)
• Name
• Type of resource
• Genre
• Origin Info
• Language
• Physical description
• Abstract
• Table of contents
• Target audience

• Note
• Subject
• Classification
• Related item
• Identifier
• Location
• Access conditions
• Extension
• Record Info

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Differences between MODS and Dublin Core

• MODS has structure
• Names
• Related item
• Subject
• MODS is more MARC-like and fits better in library
  environment
• Semantics
• Conversions
• Relationships between elements

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Using DC or MODS

• DC simple as a lowest common denominator
  between diverse metadata schemes
• DC for interoperability at coarse level
• Qualified DC still needs work
• Most DC implementations use local adjustments
  (resulting in less interoperability)
• MODS useful for
• compatibility with existing bibliographic data
• embedded descriptions in relatedItem

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LC uses of MODS

• Describing electronic resources
• AV project, web archiving
• Technician input
• web archiving (Minerva)
• Incorporation with XML resources
• METS projects
• OAI collections
• LC offers MODS, MARCXML, DC simple

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Minerva project

• Web archiving project
• Sept. 11 archive
• Olympics 2002
• Campaign 2002
• Metadata component
• Contactors to create records for resources in
  MODS
• Use for searching and as preliminary catalog
  record
• Testbed for MODS

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Fields used in Minerva project

• Title
• Name (structured form)
• Abstract
• Date captured
• Genre (value always Web site)

• Physical description (file formats)
• Identifier (base URL)
• Language
• Access conditions/rights management
• Subject (keyword or LCSH if possible)

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ltmodsgt lttitleInfogt lttitlegtBush-Cheney 2000
computer filelt/titlegtlt/titleInfogt ltname
typecorporategt ltnamePartgt Bush for President,
Inc.lt/namePartgtlt/namegt ltgenregtWeb
sitelt/genregt ltoriginInfogt ltdateCaptured
encodingISO8601"gt 20001011lt/dateCapturedgt
lt/publicationInfogt ltlanguage authority"iso639-2b"
gtenglt/languagegt ltlanguage authorityiso639-2bgts
palt/languagegt ltphysicalDescriptiongt ltinternetMedia
Typegttext/htmllt/internetMediaTypegt lt/physicalDescr
iptiongt
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ltabstractgtPresents information about Texas
Governor George W. Bush (b. 1946) and his
campaign to become the Republican nominee for
U.S. President. Contains a biographical sketch, a
schedule of appearances, and news about the
campaign. Offers access to details about issues
and speeches. Discusses how to participate in the
campaign.lt/abstractgt ltsubject authoritylcshgt ltt
opicgtRepublican Partylt /topicgtlt/subjectgt ltsubject
authoritylcshgtlttopicgtPresidential
candidateslt/topicgt lttopicgtBiographylt/topicgtlttempor
algt20th centurylt /temporalgt lt/subjectgt ltsubject
authoritylcshgtltgeographicgtUnited States
lt/geographicgtlt/subject gt ltsubject
authoritylcshgt ltgeographicgtTexaslt
/geographicgtlt/subjectgt ltidentifier
typeurigthttp//www.georgewbush.com/lt/identifier
gt lt/modsgt
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AV Prototype Project

• Exploring digital preservation for audio and
  video
• Digitally reformatted and born digital
  collections
• Use of METS with focus on metadata
• Where possible records converted from LC ILS into
  MODS also allows original input
• METS/MODS tool

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Status of MODS

• 6-month review Jun.-Dec. 2002
• version 2.0 will be available soon
• Part of the XML MARC tool kit
• Increasing interest and experimentation
• Some users have holdings as extension using
  Z39.50 holdings schema
• XML alternative to DC or full MARCXML
• LC provides conversion tools will provide a DTD

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For further information

• MODS
• http//www.loc.gov/mods
• http//www.loc.gov/mods/mods-outline.html
• METS
• http//www.loc.gov/mets
• MARCXML
• http//www.loc.gov/marcxml