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Data Management: Controlled Vocabularies Quick Guide

Controlled Vocabularies Quick Guide

Controlled vocabularies are systems of consistent terms for denoting particular entities or relationships within a given domain.   If you’ve browsed through the subject headings in a library catalog, for example, you’ve used a controlled vocabulary; those established terms make it possible for researchers to reliably recognize what they need and understand the relationships between different resources.  But controlled vocabularies describe more than just subject headings; they offer a consistent language for the background, composition, or methodology of a dataset.  Standardized terminology within a field allows for enhanced communication among researchers sharing their data, and can improve the re-discovery of data.  

Below are different systems of controlled vocabularies designed for various fields of research.   

Data Documentation Initiative

  • DDI Controlled Vocabularies
  • This metadata development group focuses on a standard descriptive language for use across the social sciences.  Their set of controlled vocabularies offers guidance on describing several different aspects of datasets, such as dates or the subjects of analyses.

Plant Ontology

  • Plant Ontology
  • This controlled vocabulary establishes terms to describe anatomy, morphology, and development for all plants.  

Chemical Entities of Biological Interest

  • ChEBI term lookup
  • This resource gives a vocabulary for molecular entities in chemical compounds; additionally, the vocabularly establishes terms for relationships among entities. 

PRO Protein Ontology

  • PRO browser
  • This vocabulary defines protein types and their relationships.

USGS Thesaurus

  • USGS Thesaurus browser and lookup
  • This resource from the United States Geological Survey provides tabs to find vocabularies for geographic features and areas, lithology, and marine planning.

Medical Subject Headings

  • MeSH browser
  • The National Library of Medicine allows researchers to browse the terms used in medical information classification.


Library of Congress

  • Library of Congress Subject Headings lookup
  • Used in libraries and institions across the United States, the Library of Congress uses a series of vocabularies for subjects, proper names, languages, relationships, and other characteristics.