The assignment of controlled vocabulary terms is a key part of the documentation processes associated with video preservation. By taking subject headings typically assigned at the collection level and extending them down to segment levels within recordings, we are creating resources that can be located at a much more granular level.

The purpose of any controlled vocabulary is to create consistency across collections and to improve the quality of searching. Ambiguity is reduced by using a single term to refer to a concept, object, place, etc. Controlled vocabularies also depend on thesauri and "used for" terms that are associated with the authoritative term so that a search on a related term finds the authoritative terms as well. Controlled vocabulary terms are used in conjunction with keyword searching to improve the quality of search results. A keyword search on a term that is controlled or associated with a controlled term will produce a result set with the controlled results at the top of the list. A set of properly applied controlled vocabulary terms also gives users the ability to browse through collections and locate items through categories of terms.

Assignment of controlled vocabulary terms to all levels of video segments within a collection is part of the annotation process by depositors. Controlled vocabulary terms and their assignments to segments result from collaborative work between catalogers and depositing scholars. Scholars propose terms they think are important for subject term identification, and catalogers determine the correct authorized terms that are to be applied.

Controlled vocabulary categories for the EVIA Project were created through a year-long process of discussions between ethnographers and librarians. After initial categories were used at the first EVIA summer institute in 2004, they were further refined to the schema now used. The categories are:

• Geography


• Language


• Social and Cultural Groupings


• Genre and Performance Types


• Venue Types


• Instruments

As new collections are accessioned, terms are added into these categories from authoritative sets such as the Library of Congress Subject Headings, the Getty Art and Architecture Thesaurus, and GEOnet.

Catalogers use the Controlled Vocabulary and Thesaurus Maintenance Tool that was created specifically for the EVIA Project. This piece of software allows librarians to import MARC files with subject terms and their associated authority information and related terms.