Research Guides @ Fordham: Digital Collections Metadata: Controlled Vocabularies

Controlled vocabularies are...

collections of descriptive terms that are normalized.
used by catalogers and indexers to describe items.
what helps users more easily locate and/or identify related items.
usually broader than the ever day keyword.
standardized groups of words or phrases.
akin to thesauri.

Controlled Vocabulary Resources

Art & Architecture Thesaurus® Online (AAT)
The AAT is one of the Getty Vocabularies. It uses generic terms to describe items within the category of art, architecture, and material culture. It is in compliance with ISO and NISO standards.
Getty Vocabularies
The Getty provides a number of different vocabularies other than the AAT. This includes the Getty Thesauraus of Geographic Names (TGN), the Cultural Objects Name Authority (CONA), the Union List of Artist Names (ULAN) and others.
Library of Congress - Linked Data
The Library of Congress' linked data service creates a way to search a number of different Library of Congress datasets. These include Library of Congress Subject Headings, Name Authorities, Classification, MARC codes, and preservation vocabularies.
Library of Congress - Name Authority File
The Name Authority File (NAF) includes standardized forms of names of persons, organizations, events, places, and titles. Unlike AAT, these controlled terms are not generic and provide a more specific set of data to use.
Library of Congress - Subject Headings
Library of Congress Subject Headings (LCSH) are very similar to the NAF except that LCSH includes broader terms that are not just limited to names. This includes terms that fall more into topical, form, or genre.
Medical Subject Headings (MeSH)
Medical Subject Headings (MeSH) is a thesaurus maintained by the National Library of Medicine for the primary use of indexing PubMed articles. However, these terms are used by most other institutions when working with items that include medical terminology.
National Agricultural Library's Agricultural Thesaurus
A controlled vocabulary maintained by the National Agricultural Library that focuses on agricultural and biological terms.

Where to Use Controlled Vocabularies

There are certain metadata fields which are more conducive for using controlled vocabulary terms. These fields are usually those that describe the content of the item that is non-specific to the individual item. This allows researchers to pull together resources that share similar attributes to make their search more robust. In some cases, the Content Management System (CMS) will only allow faceted searches if there is a controlled vocabulary in place.

Since our digital collections have many different collections it is important to make sure consistent terminology is used in controlled vocabulary fields. Without consistent terminology, users will not be able to search across collection effectively.

Creators/Contributors

Metadata fields that contain information about creators or contributors should include controlled vocabulary terminology when it is available. These include:

Persons
Organizations

Subjects

Metadata fields that highlight the subjects of an object (what the content of the item represents) are another place where controlled vocabulary terms are preferred. These types of subjects include:

Geographic
Persons
Topical
Organizations

Other Fields

There are a few other metadata fields in which using a controlled vocabulary is important.

Genre
- Examples- Maps; Pamphlets; Programs (Publications); etc.
Type
- Examples- text; moving image; still image; etc.

General Normalization of Data

There are also other metadata fields that will require some sort of 'normalization' in order to keep the metadata consistent across collections. Some of these can be filled in from a controlled vocabulary, but there are some general unspoken rules that allow both users and computers to mine the data more effectively without sifting through lists of codes. This includes:

Date (Normalized format)
Language
Call Number