The role of metadata in censuses

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The Role of Metadata in Census Data Dissemination
United Nations Regional Seminar on Census Data
Dissemination and Spatial Analysis Bangkok,
Thailand 5-8 October 2010 United Nations
Statistics Division
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Outline of presentation

• What is metadata?
• Basic roles of metadata
• Types of metadata
• Users of metadata
• Metadata in census data dissemination
• Metadata standards
• Conclusion

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What is metadata?

• It is descriptive and structured information or
  documentation about data which
• informs users about the content, quality and
  condition of data
• guides on proper usage or interpretation of data
• describes the structure of datasets, explains,
  locates, or makes it easier to retrieve, use, or
  manage data
• provides information on the processes of
  production.
• Data that define and describe other data (ISO
  definition)
• Information about information (Dion, 2006)

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Basic Roles of Metadata

• Assist in retrieving and processing data
• Support correct use of data
• Provide transparency in data
• Enhance interpretability or confidence of users
  in the information
• Improve archiving, preservation, institutional
  memory over time

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Types of metadata

• Structural metadata
• provide information about the structure of the
  dataset
• act as identifiers and descriptors of the data,
  making it possible to properly identify, retrieve
  and browse the data
• Reference metadata
• allow a thorough understanding and interpretation
  of the corresponding statistical data
• Describe the concepts, definitions, methodology
  and quality of data production and dissemination
  process, data access conditions, release policy,
  confidentiality, etc

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Users of metadata

• Metadata support the knowledge of potential user
  of statistical information. The major users
  include
• Users of statistical data
• Producers of statistical data
• Researchers on the development of statistical
  systems

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Metadata in Census Data Dissemination

• All tabulations of census data should include
• Census questions
• Reason why the questions are asked
• Conceptual definitions
• Geographic hierarchies used
• Changes since the previous census, regarding
  content, operational methods or geographic
  boundaries
• Quality indicators (ex. coverage rates and item
  non-response)
• Methodological note on the rules and methods of
  suppression
• If a long-form sample is used...
• Sampling variability of the results
• (CP, 2008)

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Metadata standards

• Currently, metadata suffer from a lack of common
  standards and guidelines
• Standardization
• ensures consistency and comparability of content
• avoids duplication and diversity of definitions
• ensures reduction in cost of data development

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Metadata standards (contd)

• Two international metadata standards are becoming
  well established
• SDMX
• DDI
• a number of international agencies have endorsed
  SDMX supported by the UN Statistical Commission
• IHSNs Microdata Management Toolkit uses the DDI
  metadata standard

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Conclusion

• Metadata are at the heart of the information
  management.
• They should be an integral part of statistical
  dissemination strategies.
• Standards for metadata management are important
• Regional and international collaboration between
  NSOs is an important consideration

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Points for discussion

• - What are the success factors of metadata?
• Strategies?
• Infrastrucure?
• Resources?
• - How to ensure the security of metadata?
• - How open or transparent the metadata can
  be?
• - How to improve standerdization of metadata?

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Thank you !