Metadata is data about data. Metadata originated in the context of digital information in databases. This chapter looks at the various standards available for digital document description in the context of bibliographic databases. It also describes the variety of metadata associated with such systems. Some of the metadata standards examined are MARC21, Dublin Core (DC), and Libsys. The second part examines metadata interoperability and mapping among these standards.
The first use of “metadata” originated in contexts related to digital information (chiefly with regard to databases). Since then, the general understanding of the term has broadened to include any kind of standardized descriptive information about resources, including nondigital ones. For example, library catalogues, abstracting and indexing services, archival finding aids, and museum documentation might all be seen as stored and retrieved based on metadata. The advantages of this are two fold. Firstly, it allows librarians, archivists, and museum documentation specialists to cooperate usefully across professional boundaries. Secondly, it enables the cultural heritage professions to communicate more effectively with those domains that also have an interest in metadata (e.g., software developers, publishers, the recording industry, television companies, the producers of digital educational content, and those concerned with geographical and satellite-based information). Therefore, metadata is critical to physical and intellectual accessibility and utility of digital document. In this sense, to quote Gilliland Swetland (2000),5 “Metadata provides us with the Rosetta stone that will make possible to decode information objects and their transformation into knowledge in the cultural heritage information systems of the twenty first century.” According to Day, metadata is defined literally as “data about data.” The term is normally understood to mean structured data about resources that can be used to help support a wide range of operations. These might include, for example, resource description and discovery, and the management of information resources and their long-term preservation.
Interoperable systems allow the exchange of information and sharing of resources. They focus on the storage of data in a standard format. The role of metadata in facilitating interoperability can be seen in number of contexts, such as:
electronic record management;
educational technology; and
library management systems.
Information about a resource needs to be embedded in the database. The catalogue record used for library management is the basis for identifying individual items and their management. Machine readable cataloguing (MARC21) covers all kinds of library materials and is used in automated library management systems in the Western libraries. Although most library management systems can import and export data in MARC21 (http://www.dublincore.org/) is currently based on a set of 15 data elements and can be used as a markup language in hypertext markup language (HTML), extensible markup language (XML), or RDF.