Dublin Core
Overview
 
The Dublin Core metadata
Metadata
The term metadata is an ambiguous term which is used for two fundamentally different concepts . Although the expression "data about data" is often used, it does not apply to both in the same way. Structural metadata, the design and specification of data structures, cannot be about data, because at...

 terms are a set of vocabulary terms which can be used to describe resources for the purposes of discovery. The terms can be used to describe a full range of web resources: video, images, web pages etc and physical resources such as books and objects like artworks http://dublincore.org/documents/dcmi-type-vocabulary/index.shtml.
Encyclopedia
The Dublin Core metadata
Metadata
The term metadata is an ambiguous term which is used for two fundamentally different concepts . Although the expression "data about data" is often used, it does not apply to both in the same way. Structural metadata, the design and specification of data structures, cannot be about data, because at...

 terms are a set of vocabulary terms which can be used to describe resources for the purposes of discovery. The terms can be used to describe a full range of web resources: video, images, web pages etc and physical resources such as books and objects like artworks http://dublincore.org/documents/dcmi-type-vocabulary/index.shtml. The full set of Dublin Core metadata terms can be found on the Dublin Core Metadata Initiative (DCMI) website http://dublincore.org/documents/dcmi-terms/. The original set of 15 classic http://dublincore.org/specifications/ metadata terms, known as the Dublin Core Metadata Element Set http://dublincore.org/documents/dces/ are endorsed in the following standards documents:


Dublin Core Metadata can be used for multiple purposes, from simple resource description, to combining metadata vocabularies of different metadata standards Metadata#Metadata standards, to providing interoperability for metadata vocabularies in the linked data cloud Linked data
Linked Data
In computing, linked data describes a method of publishing structured data so that it can be interlinked and become more useful. It builds upon standard Web technologies such as HTTP and URIs, but rather than using them to serve web pages for human readers, it extends them to share information in a...

 and semantic web implementations Semantic web
Semantic Web
The Semantic Web is a collaborative movement led by the World Wide Web Consortium that promotes common formats for data on the World Wide Web. By encouraging the inclusion of semantic content in web pages, the Semantic Web aims at converting the current web of unstructured documents into a "web of...


Background

"Dublin" refers to Dublin, Ohio
Dublin, Ohio
Dublin is a city in Franklin, Delaware, and Union counties in the U.S. state of Ohio. The population was 41,751 at the 2010 census. Dublin is a suburb of Columbus, Ohio. Approximately 57,000 people live within the Dublin school district....

, where the work originated during the 1995 invitational OCLC/NCSA Metadata Workshop, hosted in by Online Computer Library Center (OCLC), a library consortium based there, and the National Center for Supercomputing Applications
National Center for Supercomputing Applications
The National Center for Supercomputing Applications is an American state-federal partnership to develop and deploy national-scale cyberinfrastructure that advances science and engineering. NCSA operates as a unit of the University of Illinois at Urbana-Champaign but it provides high-performance...

 (NCSA). "Core" refers to the metadata terms as "broad and generic being usable for describing a wide range of resources" http://dublincore.org/documents/dces/index.shtml.
The semantics of Dublin Core were established and are maintained by an international, cross-disciplinary group of professionals from librarianship, computer science
Computer science
Computer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...

, text encoding, museum
Museum
A museum is an institution that cares for a collection of artifacts and other objects of scientific, artistic, cultural, or historical importance and makes them available for public viewing through exhibits that may be permanent or temporary. Most large museums are located in major cities...

s, and other related fields of scholarship and practice.

The Dublin Core Metadata Initiative (DCMI) incorporated as an independent entity, separating from OCLC, in 2008 that provides an open forum for the development of interoperable online metadata standards
Metadata standards
Metadata standards are requirements which are intended to establish a common understanding of the meaning or semantics of the data, to ensure correct and proper use and interpretation of the data by its owners and users...

 for a broad range of purposes and of 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.

Levels of the standard

The Dublin Core standard includes two levels — Simple and Qualified. Simple Dublin Core comprises 15 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.

Simple Dublin Core

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.

Qualified Dublin Core

Subsequent to the specification of the original 15 elements, an ongoing process to develop exemplary terms extending or refining the Dublin Core Metadata Element Set (DCMES) was begun. The additional terms were identified, generally in working groups of the Dublin Core Metadata Initiative, and judged by the DCMI Usage Board to be in conformance with principles of good practice for the qualification of Dublin Core metadata elements.

Elements refinements make the meaning of an element narrower or more specific. A refined element shares the meaning of the unqualified element, but with a more restricted scope. The guiding principle for the qualification of Dublin Core elements, colloquially known as the Dumb-Down Principle, states that an application that does not understand a specific element refinement term should be able to ignore the qualifier and treat the metadata value as if it were an unqualified (broader) element. While this may result in some loss of specificity, the remaining element value (without the qualifier) should continue to be generally correct and useful for discovery.

In addition to element refinements, Qualified Dublin Core includes a set of recommended encoding schemes, designed to aid in the interpretation of an element value. These schemes include controlled vocabularies and formal notations or parsing rules. A value expressed using an encoding scheme may thus be a token selected from a controlled vocabulary (for example, a term from a classification system or set of subject headings) or a string formatted in accordance with a formal notation, for example, "2000-12-31" as the ISO standard expression of a date. If an encoding scheme is not understood by an application, the value may still be useful to human reader.

Audience, Provenance and RightsHolder are elements, but not part of the Simple Dublin Core 15 elements. Use Audience, Provenance and RightsHolder only when using Qualified Dublin Core.
DCMI also maintains a small, general vocabulary recommended for use within the element Type. This vocabulary 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 implementers 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.

Some applications

One Document Type Definition
Document Type Definition
Document Type Definition is a set of markup declarations that define a document type for SGML-family markup languages...

 based on Dublin Core is the Open Source Metadata Framework (OMF) specification. OMF is in turn used by Rarian
Rarian
Rarian is a document cataloging system . It manages documentation metadata, as specified by the Open Source Metadata Framework . Rarian is used by the GNOME desktop help browser, Yelp. It has replaced ScrollKeeper, as originally designed.It provides an API.-External links:* *...

 (superseding ScrollKeeper
ScrollKeeper
ScrollKeeper is a document cataloging system. It manages documentation metadata, as specified by the Open Source Metadata Framework . ScrollKeeper was used by the GNOME desktop help browser, Yelp, but has since been replaced by Rarian. It was also used by the KDE help browser and ScrollServer...

), which is used by the GNOME
GNOME
GNOME is a desktop environment and graphical user interface that runs on top of a computer operating system. It is composed entirely of free and open source software...

 desktop and KDE
KDE
KDE is an international free software community producing an integrated set of cross-platform applications designed to run on Linux, FreeBSD, Microsoft Windows, Solaris and Mac OS X systems...

 help browsers and the ScrollServer documentation server. PBCore
PBCore
The PBCore metadata standard was created by the public broadcasting community in the United States of America for use by public broadcasters and related communities. Initial development funding for PBCore was provided by the Corporation for Public Broadcasting...

 is also based on Dublin Core. The Zope
Zope
Zope is a free and open-source, object-oriented Web application server written in the Python programming language. Zope stands for "Z Object Publishing Environment", and was the first system using the now common object publishing methodology for the Web...

 CMF's
Zope Content Management Framework
The Zope Content Management Framework is a series of free software tools for Zope that forms a framework providing many of the key services a content management system would need. The CMF can be used as a standalone product, or it can be built on top of, for example in Plone's or Nuxeo CPS's...

 Metadata products, used by the Plone
Plone (content management system)
Plone is a free and open source content management system built on top of the Zope application server. In principle, Plone can be used for any kind of website, including blogs, internet sites, webshops and internal websites. It is also well positioned to be used as a document publishing system and...

, ERP5
ERP5
ERP5 is an open source ERP based on Python and Zope. It has the particularity of being based on an unified Model to describe its implementation.- Unified Model :...

, the Nuxeo CPS Content management system
Content management system
A content management system is a system providing a collection of procedures used to manage work flow in a collaborative environment. These procedures can be manual or computer-based...

s, SimpleDL
SimpleDL
SimpleDL is digital collection management software that allows for the upload, description, management and access of digital collections and is UTF-8 compatible. SimpleDL is not limited by format and is capable of handling documents, PDFs, images, videos, audio files, and data only objects...

, and FedoraCommons also implement Dublin Core.

DCMI also maintains a list of projects using Dublin Core on its website.

See also

  • Metadata registry
    Metadata registry
    A metadata registry is a central location in an organization where metadata definitions are stored and maintained in a controlled method.-Use of Metadata Registries:...

  • Metadata Object Description Schema
  • Metadata from Wikiversity
  • Semantic Web
    Semantic Web
    The Semantic Web is a collaborative movement led by the World Wide Web Consortium that promotes common formats for data on the World Wide Web. By encouraging the inclusion of semantic content in web pages, the Semantic Web aims at converting the current web of unstructured documents into a "web of...

  • Ontology (computer science)
    Ontology (computer science)
    In computer science and information science, an ontology formally represents knowledge as a set of concepts within a domain, and the relationships between those concepts. It can be used to reason about the entities within that domain and may be used to describe the domain.In theory, an ontology is...

  • Open Archives Initiative
    Open Archives Initiative
    The Open Archives Initiative is an attempt to build a "low-barrier interoperability framework" for archives containing digital content . It allows people to harvest metadata...

  • Controlled vocabulary
    Controlled vocabulary
    Controlled vocabularies provide a way to organize knowledge for subsequent retrieval. They are used in subject indexing schemes, subject headings, thesauri, taxonomies and other form of knowledge organization systems...

  • Interoperability
    Interoperability
    Interoperability is a property referring to the ability of diverse systems and organizations to work together . The term is often used in a technical systems engineering sense, or alternatively in a broad sense, taking into account social, political, and organizational factors that impact system to...

  • METS
    METS
    The Metadata Encoding and Transmission Standard is a metadata standard for encoding descriptive, administrative, and structural metadata regarding objects within a digital library, expressed using the XML schema language of the World Wide Web Consortium...

    , a metadata standard maintained by the Library of Congress
    Library of Congress
    The Library of Congress is the research library of the United States Congress, de facto national library of the United States, and the oldest federal cultural institution in the United States. Located in three buildings in Washington, D.C., it is the largest library in the world by shelf space and...

     for the Digital Library Federation
  • Preservation Metadata: Implementation Strategies (PREMIS)
    Preservation Metadata: Implementation Strategies (PREMIS)
    PREMIS is an international working group concerned with developing metadata for use in digital preservation....


Related Software

  • Dublin Core Meta Toolkit (Conversion of Access, MySQL, or CSV data to DublinCore metadata)
  • Fedora
    Fedora (software)
    Fedora is a modular architecture built on the principle that interoperability and extensibility is best achieved by the integration of data, interfaces, and mechanisms as clearly defined modules...

     repository architecture and Project (An open-source software system capable of implementing OAI-PMH (and thus Dublin Core).
  • Omeka
    Omeka
    Omeka is a free, open source web publishing system for online digital archives, and uses an unqualified Dublin Core metadata standard. Completely web-based, it allows users to publish cultural heritage objects, extend its functionality with themes and plugins, and curate online exhibits with...

    , A free, open-source, unqualified Dublin-Core compliant web-publishing system for digital archives.
  • The Archivist's Toolkit is a self-described as an "Archival Data Management system" able to work with the Dublin Core format. It will soon be merged with Archon
    Archon
    Archon is a Greek word that means "ruler" or "lord", frequently used as the title of a specific public office. It is the masculine present participle of the verb stem ἀρχ-, meaning "to rule", derived from the same root as monarch, hierarchy, and anarchy.- Ancient Greece :In ancient Greece the...

    , which is ambiguous as to its OAI support.
  • ICA-AtoM, a web-based archival description/publication software that can serve as an OAI-PMH repository and uses OAI-PMH as the main language for remote data exchange.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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