Dublin Core

Dublin Core integration in Canadian government

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Introduction

See also Digital Libraries Glossary, Resource Description and Access (RDA) & CVHL / BVCS Dublin Core Records

Dublin Core (DC) is a metadata standard created by the Dublin Core Metadata Initiative (DCMI), which provides a semantic vocabulary for describing the "core" information properties of digital materials. It is named after a planning meeting in Dublin, Ohio.

Dublin Core is defined as "fifteen metadata elements for resource description in a cross-disciplinary information environment". It provides a simple, standardized set of conventions for describing items to make them easier to find. DC is widely used to describe digital materials such as video, sound, image, text, and composite media like web pages. Implementations of DC make use of XML and the Resource Description Framework (See NISO Standard Z39.85-2007). The "Dublin" in the name refers to Dublin, Ohio where the work originated in a workshop in 1995 at OCLC, the well-known library consortium. The "Core" refers to the metadata element set, a basic but expandable "core" list. The semantics of Dublin Core were established and are maintained by an international, cross-disciplinary group of professionals from librarianship, computer science, text encoding, the museum community, and other related fields of scholarship and practice. The Dublin Core Metadata Initiative is an organization and open forum developing interoperable online metadata standards that support a broad range of purposes and business models. DCMI's activities include consensus-driven working groups, global conferences and workshops, standards liaison, and educational efforts to promote widespread acceptance of metadata standards and practices.

Simple and Qualified DC

The Dublin Core standard includes two levels: Simple and Qualified. Simple Dublin Core comprises fifteen elements; Qualified Dublin Core includes three additional elements (Audience, Provenance and RightsHolder), as well as a group of element refinements (also called qualifiers) that refine the semantics of the elements in ways that may be useful in resource discovery.

The Simple Dublin Core Metadata Element Set (DCMES) consists of 15 metadata elements:

1. Title
2. Creator
3. Subject
4. Description
5. Publisher
6. Contributor
7. Date
8. Type
9. Format
10. Identifier
11. Source
12. Language
13. Relation
14. Coverage
15. Rights

Each Dublin Core element is optional and may be repeated. The DCMI has established standard ways to refine elements and encourage the use of encoding and vocabulary schemes. There is no prescribed order in Dublin Core for presenting or using the elements. Full information on element definitions and term relationships can be found in the Dublin Core Metadata Registry Dublin Core Metadata Registry.

Qualified Dublin Core

After the original 15 elements were specified, an ongoing process extended the Metadata Element Set (DCMES). Additional terms were identified in working groups and judged by the Usage Board to conform with principles of good practice for Dublin Core metadata elements. The goal is to make an element narrower or more specific; a refined element shares meaning of the unqualified element but in a more restricted way. The guiding principle for qualification of elements - known as the Dumb-Down Principle - is that an application that does not understand a specific refinement should ignore it and treat it as an unqualified element. While this results in loss of specificity, the remaining element (without qualifier) is adequate for discovery. In addition to refinements, Qualified Dublin Core includes a set of recommended encoding schemes designed to aid in interpretation. A value expressed using an encoding scheme may be a token selected from a controlled vocabulary (e.g., term from a classification system or set of subject headings) or a string formatted in accordance with a formal notation (e.g., "2000-12-31" as standard expression of a date). If encoding is not understood by computers, it may be useful to use human readers. DCMI maintains a small vocabulary recommended for use within element Type; this currently consists of 12 terms.

Syntaxes

Syntax choices for DC metadata depend on a number of variables, and "one size fits all" prescriptions rarely apply. When considering an appropriate syntax, it is important to note that Dublin Core concepts and semantics are designed to be syntax independent, are equally applicable in a variety of contexts, as long as the metadata is in a form suitable for interpretation both by machines and by human beings. The Dublin Core Abstract Model provides a reference model against which particular DC encoding guidelines can be compared, independent of any particular encoding syntax. Such a reference model allows implementors to gain a better understanding of the kinds of descriptions they are trying to encode and facilitates the development of better mappings and translations between different syntaxes.

References

• Allinson, J. (2008). Describing scholarly works with Dublin Core: A functional approach. Library Trends 57(2), 221-243.
• Campbell, D. (2000). Picture this: a working combination of Z39.50, the Dublin Core and MARC21. A paper given by Debbie Campbell, Manager, Infrastructure Projects, National Library of Australia, at ALIA 2000 "Capitalising on knowledge the information profession in the 21st century" 24-26 October 2000 in Canberra.
• CDP Metadata Working Group. (2006). Dublin Core metadata best practices: version 2.1.1. BCR. Retrieved from http://www.bcr.org/dps/cdp/best/dublin-core-bp.pdf
• Greenberg J. Author-generated Dublin Core Metadata for Web Resources: A Baseline Study in an Organization.
• Hillmann, D. (2001). Using dublin core. DublinCore Metadata Initiative. Available at http://dublincore.org/documents/2001/04/12/usageguide/.
• Sugimoto S, Baker T, Weibel S. (2010). Dublin Core: process and principles. Digital Libraries: People, Knowledge, and Technology, 25–35, 2010.
• “Using Dublin Core” – official usage guide
• Dublin Core Metadata Initiative
• Dublin Core Metadata Initiative Publishes DCMI Abstract Model (Cover Pages, March 2005)
• Metadata Object Description Schema (MODS)