Keyword vs. Subject Searching

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Sometimes it is beneficial to try a subject search on your topic, which can give you more precise results. What is the difference between keyword and subject searching?

Subject	Keyword
Description A subject heading search only searches in the subject/descriptor field. If you do not know a subject heading to search on, do a keyword search first. When you find a good resource, check out the subject headings listed in the record and use it as a gateway to find similar materials. Note: you can combine subject headings and keywords in your search	Description A keyword search does not use a controlled vocabulary and will find your search terms in any number of descriptive fields (title, abstract, etc.). Before beginning a keyword search, spend a few minutes brainstorming synonyms and alternative spellings. A thesaurus can help with this process.
Quick Comparison Narrow search (Retrieves potentially fewer items) Searches only in the subject/descriptor field Search terms must be selected from a controlled vocabulary list like the Library of Congress Subject Headings or a database’s thesaurus High degree of relevancy	Quick Comparison Broad Search (Retrieves a potentially large number of items) Searches in any number of descriptive fields like title, subject, and/or document text Search terms can be any concepts or words/phrases that you choose High degree of inclusiveness
Examples of Keyword Terms Native Americans Cars Movies or films United States and civil war	Examples of Subject Headings Indians of North America Automobiles Motion pictures United States History Civil War, 1861-1865
Use When A subject heading on your exact topic exists Want precise results immediately	Use When There is no subject heading for your topic (topic is very current) Database does not allow subject searches Subject headings are too broad or too specific

Subject

Keyword

Description

A subject heading search only searches in the subject/descriptor field. If you do not know a subject heading to search on, do a keyword search first. When you find a good resource, check out the subject headings listed in the record and use it as a gateway to find similar materials. Note: you can combine subject headings and keywords in your search

Description

A keyword search does not use a controlled vocabulary and will find your search terms in any number of descriptive fields (title, abstract, etc.). Before beginning a keyword search, spend a few minutes brainstorming synonyms and alternative spellings. A thesaurus can help with this process.

Quick Comparison

Narrow search (Retrieves potentially fewer items)
Searches only in the subject/descriptor field
Search terms must be selected from a controlled vocabulary list like the Library of Congress Subject Headings or a database’s thesaurus
High degree of relevancy

Quick Comparison

Broad Search (Retrieves a potentially large number of items)
Searches in any number of descriptive fields like title, subject, and/or document text
Search terms can be any concepts or words/phrases that you choose
High degree of inclusiveness

Examples of Keyword Terms

Native Americans
Cars
Movies or films
United States and civil war

Examples of Subject Headings

Indians of North America
Automobiles
Motion pictures
United States History Civil War, 1861-1865

Use When

A subject heading on your exact topic exists
Want precise results immediately

Use When

There is no subject heading for your topic (topic is very current)
Database does not allow subject searches
Subject headings are too broad or too specific