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Digital Collections Metadata: Controlled Vocabularies

This guide's primary function is to explain what metadata is and what metadata should be used for Fordham Libraries' Digital Collections.

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

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.


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

  • Persons

  • Organizations


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