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 i

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

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) 3

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 4

Types of metadata Structural metadata Reference 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 5

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 6

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 (C&P, 2008)

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 8

Metadata standards (cont’d) Two international metadata standards are becoming well established SDMX DDI a number of international agencies have endorsed SDMX; supported by the UN Statistical Commission IHSN’s Microdata Management Toolkit uses the DDI metadata standard S 9

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 10

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?

Thank you !