7. Metadata

Metadata literally means "data about data." Any catalogue, card or online, contains metadata. But, today, the term is applied to the value-added information that information- specialists create to arrange, describe, track and otherwise enhance access to information objects.

Metadata is used to describe, in a standardized way, the minimum set of information that is necessary to locate a document. In addition, metadata provides a standard way to describe network-accessible material; metadata enable the user to make more precise queries, metadata help the search engines to present hits that are grouped by subject rather than a random mix.

Or in other words, metadata are data that describe the attributes of a resource; characterise its relationships; support its discovery, management, and effective use; and exist in an electronic environment. While this definition reflects the metadata ideal, in reality, most metadata schemes rarely accomplish all of these functions equally well. Therefore an authority control system must be understood and placed to each metadata scheme chosen by the institution.

An authority control system is based on four factors: controlled operating environment, trained provider, application of standards, and reference to authoritative lists. Therefore, a trained cataloguer of audiovisual material should be included in the selection and digitisation workflow.

The most common metadata systems today are the MARC (Machine Readable Cataloguing) bibliographic record and the DC (Dublin Core) Metadata Element Set. Both require adjustments for audiovisual collections. In the EBU Technical Review, Dublin Core Metadata Element Set is recommended. Depending on its concerns an institution may choose one scheme over another.

Metadata can be embedded within the document itself. Standard Generalized Markup Language (SGML) is one of the most common markup languages used for metadata, along with its related codes Hyper Text Markup Languages (HTML), and the newer Extensible Markup Language (XML). Metadata can also be stored separately from the source (e.g. external catalogue) or separate but linked to the resource (e.g. linked with the digital object in a repository structure). Each strategy has particular benefits and disadvantages.

Information specialists along with archivists and cataloguers should create the metadata for audiovisual archives. Reference should be made to authoritative lists. Audiovisual archives should be part of the scholarly information culture and not the popular information culture.

In the metadata creation process, preservation metadata should be a key component in the preservation and management of the digital collection and must be designed to support future preservation strategies.