In the previous section, examples of data structures or metadata element sets have been introduced. "The choice of terms or words (data values) and the selection, organization, and formatting of those words (data content) are two other types of standards that must be used in conjunction with an agreed-upon data structure" (CCO Introduction, 2005). This section provides resource related to data values and data content.
6.1 Using controlled vocabularies for names, titles, and subjects
• Almost all metadata standards require or recommend the use of controlled vocabularies for some elements.
Examples from Dublin Core 1.1:
Element Name Subject Label: Subject and Keywords Definition: A topic of the content of the resource. Comment: Typically, Subject will be expressed as keywords, key phrases or classification codes that describe a topic of the resource. Recommended best practice is to select a value from a controlled vocabulary or formal classification scheme.
Element Name: Type Label: Resource Type Definition: The nature or genre of the content of the resource. Comment: Type includes terms describing general categories, functions, genres, or aggregation levels for content. Recommended best practice is to select a value from a controlled vocabulary (for example, the DCMI Type Vocabulary [ DCT1 ]). To describe the physical or digital manifestation of the resource, use the FORMAT element.
- Examples from VRA Core 3.0:
- CULTURE
Qualifiers: None
Description: The name of the culture, people (ethnonym), or adjectival form of a country name from which a Work or Image originates or with which the Work or Image has been associated.
Data Values : recommend AAT, LCSH
- CREATOR
Qualifiers
Creator.Role
Creator.Attribution
Creator.Personal name
Creator.Corporate name
Description: The names, appellations, or other identifiers assigned to an individual, group, corporate body, or other entity that has contributed to the design, creation, production, manufacture, or alteration of the work or image.
Data Values (controlled): recommend ULAN and AAAF (LC authority files).
The following controlled vocabularies are usually recommended by the metadata standards or best practice guide.
DCMI Type Vocabulary
http://dublincore.org/documents/dcmi-type-vocabulary/The DCMI Type Vocabulary provides a general, cross-domain list of approved terms that may be used as values for the Resource Type element to identify the genre of a resource.
[MIME] Internet Media Types
http://www.iana.org/assignments/media-types/
May be used as values for the Format element.
ISO 639 - Codes for the representation of names of languages.
http://www.oasis-open.org/cover/iso639a.html
May be used as values for the Language element.
ISO 3166 - Codes for the representation of names of countries.
http://www.oasis-open.org/cover/country3166.html
Note: Only a small number of thesauri and classification schemes are listed below. They are frequently mentioned in metadata standards. A more completed list is available online.
Subject Headings
LC Subject Headings (LCSH)
Website about Web access to LCSH http://www.loc.gov/cds/classweb.htmlFAST (Faceted Application of Subject Terminology) Authority File
http://www.oclc.org/research/projects/fast/
FAST adapted the LCSH with a simplified syntax. It retains the very rich vocabulary of LCSH while making the schema easier to understand, control, apply, and use. The headings have been built into FAST authority records.
Current search interface: http://fast.oclc.org/Medical Subject Headings (MESH)
http://www.nlm.nih.gov/mesh/meshhome.html
MeSH consists of sets of terms naming descriptors in a hierarchical structure that permits searching at various levels of specificity. There are 22,568 descriptors in MeSH. In addition to these headings, there are more than 139,000 headings called Supplementary Concept Records (formerly Supplementary Chemical Records) within a separate thesaurus.Thesauri
Art and Architecture Thesaurus (AAT)
http://www.getty.edu/research/tools/
vocabulary/aat/index.html
The AAT is a structured vocabulary of more than 133,000 terms, descriptions, bibliographic citations, and other information relating to fine art, architecture, decorative arts, archival materials, and material culture.Library of Congress Thesauri
http://www.loc.gov/pmei/lexico/tgm1/brsearch.htmlThesaurus for the Global Legal information Network (GLIN)
http://www.loc.gov/lexico/servlet/lexico?usr=pub-375:0&op=frames&db=GLIN
Now used for The Global Legal Information Network's multi-national database of legislation, this thesaurus has been under continuous development since 1950.Legislative Indexing Vocabulary (LIV)
http://www.loc.gov/lexico/servlet/lexico?usr=pub-375:0&op=frames&db=LIV
The thesaurus was developed by the Congressional Research Service for use with legislative and public policy material.Thesaurus for Graphic Materials I: Subject Terms (TGM I)
http://lcweb2.loc.gov/pp/tgmiquery.html
A thesaurus consisting of thousands of terms and numerous cross references for the purpose of indexing visual materials.Thesaurus for Graphic Materials II: Genre and Physical Characteristic Terms (TGM II)
http://lcweb2.loc.gov/pp/tgmiquery.html
A thesaurus of more than 600 terms, developed by the Library of Congress Prints and Photographs Division, with input from other archival image repositories.
Classification schemes
Dewey Decimal Classification (DDC)
Website about DDC http://www.oclc.org/dewey/default.htm
The ACM Computing Classification System [1998 Version], Valid in 2003, Association for Computing Machinery
http://www.acm.org/class/1998/
The Union List of Artist Names (ULAN)
http://www.getty.edu/research/conducting_research/vocabularies/ulan
The ULAN is a structured vocabulary containing more than 225,000 names and biographical and bibliographic information about artists and architects, including a wealth of variant names, pseudonyms, and language variants.
The Getty Thesaurus of Geographic Names (TGN)
http://www.getty.edu/research/conducting_research/vocabularies/tgn/
The TGN is a structured, world-coverage vocabulary of 1.3 million names, including vernacular and historical names, coordinates, place types, and descriptive notes, focusing on places important for the study of art and architecture.
LC Name Authority file = Anglo-American Authority File (AAAF)
http://authorities.loc.gov/
Includes several millions of name authority records for personal, corporate, meeting, and geographic names.