Dublin Core Metadata

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Dublin Core Metadata

• Howard Besser
• UCLA School of Education Information
• http//www.gseis.ucla.edu/howard

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Metadata for Digital Libraries-

• Models for Digital Libraries
• Importance of Metadata Standards
• Types and Uses of Metadata
• Discovery Metadata The Dublin Core

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Key problems were facing

• Discovery
• Longevity-
• Interoperability-

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Traditional Digital Library Model
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Ideal Digital Library Model
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For Interoperability Digital Libraries Need
Standards

• Descriptive Metadata for consistent description
• Discovery Metadata for finding
• Administrative Metadata for viewing and
  maintaining
• Structural Metadata for navigation
• ... Terms Conditions Metadata for controlling
  access...

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Why are Standards and Metadata consensus
important?

• Managing digital files over time
• Longevity
• Interoperability
• Veracity
• Recording in a consistent manner
• Will give vendors incentive to create
  applications that support this

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Why Standards?

• Why do we need standards?
• To make information universally available to
  users
• facilitate sharing and interchange of
  information
• To preserve information (make it safe from
  changes in hardware and software)
• Standards only work if communities widely accept
  them, but theyre necessary for communities to
  work together

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Why are you Managing this Information?

• Organizational mission type
• Users
• Uses

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Questions to Ask

• What communities is this standard designed for?
• What type of information is this standard
  designed to handle?
• What functions is this standard designed to
  serve?
• What previous standards is it built upon?
• Does the standard prescribe how to create new
  records (or parts of records), or how to map from
  existing records?
• How far does the standard go? Semantics Does it
  define element sets? Rules? Syntax?-

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What is Metadata

• Structured data describing other data used to
  find or help manage information resources
• Aids in interoperability
• Titles, dates, captions, cataloging and indexing
  data, file headers, rights info, provenance, code
  books, transaction logs, ...
• One persons metadata is anothers data

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Sorting through the Standards Morass

• Data Structures (DC, CDWA, MARC, VRA Core, TEI,
  EAD, MESL data dict)
• Data Interchange (Z39.50)
• Data Values/vocabularies (LCSH, AAT, ULAN, TGN)
• Data Content/syntax (AACR2)

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Semantics/Syntax/Structure

• Semantics
• meaning, as defined by a community to meet their
  particular needs (DC)
• Syntax
• a systematic arrangement of data elements for
  machine processing
• facilitates the exchange and use of metadata
  among various applications (HTML, XML, RDF)
• Structure
• a formal arrangement of the syntax with the goal
  of consistent representation of the semantics
  (rules defining field contents like 1/11/99)

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What is MetadataTypes Uses

• lots of different ways of dividing the clusters

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Uses of Metadata

• Discovery Retrieval
• Identification/Provenance
• Rights Management
• Viewing
• Integrity
• Longevity
• Content rating

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Containers and Packages of MetadataWarwick, not
MARC

• modular
• overlapping
• extensible
• community-based
• designed for a networked world to aid commonality
  btwn communities while still providing full
  functionality within each community

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Some different schemes where Metdata is kept

• embedded withing the object (HTML tags)
• in a separate related DB maintained by same
  organization (OPAC, MOA II)
• in a separate DB maintained by a separate
  organization (Books in Print, ratings systems)
• derived on-the-fly from a different scheme
  (MARC-to-DC)

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Collaborative Metadata Projects

• Dublin Core
• NSF/ERCIM Digital Collaboratory
• OCLC CORC Project-
• Visual Resources Association (VRA) Core
• Encoded Archival Description (EAD)
• Computerized Interchange of Museum Information
  (CIMI)-
• Records Export for Art and Cultural Heritage
  (REACH)

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Dublin Core (3/95)

• improve resource discovery
• anticipate precision problems of Web
  Crawler-based searching tools
• existing metadata could be dumbed down
• elements should be simple to understand and use,
  so that any individual should be able to assign
  terms him/herself
• software might eventually automatically generate
  very base-level metadata

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Dublin Core

• Title
• Creator
• Subject
• Description
• Publisher
• Contributors
• Date
• Type

• Format
• Identifier
• Source
• Language
• Relation
• Coverage
• Rights

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Dublin Core

• every element is both optional and repeatable
• elements are cross-disciplinary
• elements are extensible by organized communities
• can employ a syntax such as htmls
  ltMETAgt tagset for use by Spiders and Harvesters
• May 2000 DLF Metadata Harvesting Project

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DC Qualifiers

• allows one community to express important nuances
  and qualifications, while still making the basic
  importance available to communities with simple
  needs
• our community can reflect alternate title,
  transliterated title, and main title, yet they
  will all be found under a simple Web search under
  title

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Discovery MetadataRecent History

• Dublin Core (3/95)
• Warwick Framework (4/96)
• Image Metadata Workshop (9/96)
• Canberra, Helsinki, ... DC (98)
• Digital Library Collaboratory (97-)
• DC-8, Frankfurt 10/99

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Dublin Core--further work

• Warwick Framework
• metadata packages for extensible functions
• layed groundwork for RDF
• Canberra Qualifiers
• refining the semantics of the element set to
  provide more precise info
• SUBELEMENT, SCHEME, LANG
• Granularity
• no hierarchical relationships w/i a given DC
  record only one record per discrete object
  (collection or item-level), and relationship
  field plus qualifier links them

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The Research Process and Functional Categories
of Metadata

• Discovery
• Retrieval
• Collation
• Analysis
• Re-presentation

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Metadata Mapping-

• Crosswalks
• Resource Description Framework (RDF)

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Crosswalks

• mapping btwn differing metadata structures
• eliminate the need for monolithic, universally
  adopted standards
• focus on flexibility and interoperatiblity
• RDF-based metadata registries

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Crosswalk Example
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Resource Description Framework (RDF, spec
released 2/99)

• W3C Metadata activity
• designed to move the Web beyond simple links to
  semantically-rich relationships btwn resources
• metadata application using XML as a common syntax
  for exchange and processing
• flexible architecture for managing diverse
  application-specific metadata packets that can be
  processed by machines
• associates resources, property types, and
  corresponding values
• http//www.w3.org/RDF/

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RDF

• Resources (character strings, names, digital
  objects)
• Property (is the author of)
• Value
• resourcespropertiesrelationships
• many different relationships can be reflected

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XML-encoded RDF

• lt?xmlnamespace nshttp//www.w3.org/RDF/RDF
  prefix"RDF" ?gt
• lt?xmlnamespace nshttp//purl.oclc.org/DC/
  prefix"DC" ?gt
• ltRDFRDFgt
• ltDCCreatorgtHoward Besserlt/DCCreatorgt
• lt/RDFDescriptiongt
• lt/RDFRDFgt

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Should you start building with RDF today?

• Tools are primitive
• Standard still likely to evolve

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Metadata for Digital Libraries

• Howard Besser
• UCLA School of Education Information
• Baca, Murtha (ed). Introduction to Metadata, Los
  Angeles Getty Information Institute, 1998
• http//www.getty.edu/gri/standard/intrometadata/
• http//sunsite.Berkeley.EDU/Imaging/Databases/sta
  ndards
• http//sunsite.Berkeley.EDU/moa2/
• http//sunsite.Berkeley.EDU/Longevity/
• http//www.ifla.org/II/metadata.htm
• http//purl.oclc.org/metadata/dublin_core/
• http//purl.oclc.org/corc/
• http//lcweb.loc.gov/ead/
• http//www.gseis.ucla.edu/howard/image-meta.html
• http//www.gseis.ucla.edu/howard/Metadata/UC-May0
  0/
• http//sunsite.berkeley.edu/Metadata/sp2000.html