An Introduction To Metadata
About This Document
This briefing document provides an introduction to metadata.
What Is Metadata?
Metadata is sometimes defined literally as 'data about data'. More usefully, the term is understood to mean structured data about resources. The fact that the data is structured - broken down into very specific pieces - enables a range of automated processes to be built around the data to provide services.
Traditional 'Metadata'?
In one sense, metadata is not a new concept. Library catalogues, abstracting and indexing services, directories of resources and institutions, archival finding aids and museum documentation all contain structured information.
What is the Value of Metadata
Firstly, it enables librarians, archivists and museum documentation professionals to work across institutional and sector boundaries to provide more effective resource discovery to the benefit of enquirers, students and researchers.
Secondly, it enables cultural heritage professions to communicate more effectively with other domains that also have an interest in metadata, such as publishers, the recording industry, television companies, producers of digital educational content, software developers and those concerned with geographical and satellite-based information.
Metadata Standards
Because so many communities now use metadata, there are a bewilderingly large number of standards and formats in existence or in development. Metadata is used for resource description and discovery; recording intellectual property rights and access data; and technical information relating to the creation, use and preservation of digital resources.
Metadata Encoding
Metadata is recorded in formats (e.g. MARC 21) or implementations of Mark-up Languages and Document Type Definitions (DTD). The main standards are:
- SGML
- Standard Generalised Mark-up Language.
- XML
- Extensible Mark-up Language.
Metadata for Libraries
Important metadata standards for use in a library context are:
- MARC 21
- A means of encoding metadata defined in bibliographic cataloguing rules.
- ISBD series
- International Standard for Bibliographic Description.
- ONIX
- A range of international standards for electronic information messages (about books, serials and licensing and rights) for the book industry.
Metadata for Archives
Important metadata standards for use in an archives context are:
- EAD
- Encoded Archival Description; a means of encoding metadata defined in archival cataloguing rules.
- ISAD(G)
- International Standard for Archival Description.
Metadata for Museums
Important metadata standards for use in a museum context are:
- SPECTRUM
- The UK and international standard for collections management.
- CIDOC-CRM
- The CIDOC conceptual reference model (ISO 21127:2006).
Metadata for the Digital World
Important metadata standards for use in a digital context are:
- Dublin Core (DC)
- Defines 15 metadata elements for simple resource discovery. Qualifiers for some of these elements enable more detail to be recorded. Further elements have now been defined to use in specific fields.
- DC Application Profiles
- A set of DC elements defined for use in the context of specific communities of practice; for example, education, libraries, collections and scholarly works.
