Metadata and Interoperability

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Metadata and Interoperability
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What is Interoperability?

• Interoperability refers to the ability of two or
  more DL systems to interact with one another and
  exchange data according to a prescribed method in
  order to achieve predictable results

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Why Interoperability?

• Rapid growth in web accessible DLs
• Users cannot be expected to independently access
  each relevant DL
• Required Mechanism for seamless resource
  discovery across DLs

Metadata plays a significant role in
interoperability of DLs
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Approaches

• Development of crosswalks between different
  metadata schemes
• E.g. Between DC and MARC
• Protocols for cross-system searching
• E.g. Z39.50 (e.g. NDLTD, library OPACs)
• Citation linking using metadata
• E.g. OpenURL
• Metadata harvesting
• E.g. OAIPMH (Open Archives Initiative Protocol
  for Metadata Harvesting)

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Metadata Cross-Walks

• Mappings between metadata schemes
• Facilitate automatic translation and import of
  content from another system
• Use of a standard scheme (e.g. MARC) as a
  switching scheme to exchange data between systems
  using different schemes
• E.g. DC and MARC, CCF and MARC

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Cross-System Searching

• Z39.50 IR protocol (over TCP/IP)
• Metadata remains in local repositories
• Local repositories support Z39.50 compliant
  interfaces (background processes) to receive
  search queries, process and send out results as
  per the protocol
• Federated Searches e.g. NDLTD
• Analogy web meta search engines

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Citation Linking OpenURL

• How to link from bibliographic records to
  full-text articles?
• How to link from a citation in an article in
  journal X to full text article in journal Y?
• Solutions
• Use of DOI (Digital Object Identifier) by
  CROSSREF member publishers
• Use of metadata for generating link URL (OpenURL)
  (e.g. ISSN, vol no., issue no., page)

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OAI and Metadata Harvesting

• OAI Open Archives Initiative
• Origination E-Print archive community
• Web accessible archives of scholarly research
  papers
• Need for federating access across e-print
  archives
• Development of OAI interoperability framework
  based on metadata harvesting
• OAIPMH Protocol (current version 2.0)
• Application beyond e-print community
• General model for interoperability across all
  types of digital libraries
• Supported by NSF, DLF and CNI

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Operation of OAI-PMH

• Two key players
• Data providers and Service providers
• Data providers
• Maintain web-based repositories that support the
  OAIPMH as a means of exposing metadata (in XML,
  with DC tagging for e-print archives)
• Registers with OAI
• Service providers
• Issue OAIPMH requests to data providers
• Obtain the metadata and provide various services
• Register with the OAI

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Operation of OAI-PMH

• OAIPMH protocol
• Defines a mechanism for harvesting XML-formatted
  metadata from repositories
• Ease of implementation by data providers
• Software interface for parsing protocol requests,
  content extraction, XML tagging and transmission
  via HTTP to requestor
• Example OAIPMH system
• E-Print archives set up using eprints.org
  sosftware
• Example service provider ARC (http//arc.cs.odu.e
  du/)