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Database Search Fundamentals: Subjects vs. Keywords


Keywords are natural language words we use to denote or describe a topic. This is the most common method when using a search engine like Google.

Subjects are pre-defined, authoritative words or phrases (called a controlled vocabulary) used by databases to consistently describe and systematically organize content.


Why is this important?

  • The term(s) we might use often differ from those used in a particular discipline or the controlled vocabulary used by a database for indexing. Examples of keywords vs. subjects:




  • Subjects are more precise and will retrieve more relevant results. Using subjects can also help you to focus on a particular aspect of a broad topic more effectively than by combining keywords. For example:



Too few results or too many?

Keywords are more flexible and allow for more combinations of concepts, but can yield too many, too few, and often irrelevant results. Moreover, databases search for keywords anywhere in the record, which may not correlate to the actual content of the article, book, etc.

Subjects allow for less flexibility and you need to know the exact terminology, but assigned subjects more accurately describe the content of an article or book.


How do I find subject headings?

Option 1:

  • ​Conduct a keyword search.
  • Look for the most relevant results​ and m​ake note of the subjects listed under the citation information.
  • Click on the title of a relevant result to open the full record. This will include a linked listing of the subjects that source is classified under.
  • Click on a subject and it will redo the search and bring up all the results on that subject.


Option 2*:

If the individual database you are using has a thesaurus you can search or browse for subject terms. Look for a link in the top navigation bar for a link to either index(es), thesaurus, subject terms, or subjects.

*Not available when using the combined OneSearch discovery because thesauruses are database specific.

*Database interfaces vary and not all provide a subject thesaurus.