When searching library databases you have the option to use both keywords and subject terms.
Keyword searching involves using the words and phrases that describe your research topic. As a researcher, you determine what keywords you are going to type into the search box within a database. Keywords are generally broad terms that focus on using natural, conversational language. Keyword searching within a database is a comprehensive, unfocused search that results in a large number of search results that may or may not be relevant to your topic.
Subject searching involves using specific vocabulary, often referred to as "controlled vocabulary", within a database. Most databases contain a controlled vocabulary index of standardized, pre-defined terms used to describe concepts and categorize articles based on their content or subject. These controlled vocabulary indexes can also be referred to as Subjects, Subject Headings, Subject Terms, Descriptors, Thesaurus, or Index terms. Subject searching is precise and uses higher order language and scientific terminology. Subject searching within a database will result in fewer, more relevant search results.
The following table outlines the differences between subjects and keywords:
|Pre-defined, higher order terminology||Natural (conversational) language|
|Only searches the subject or descriptor field in a database record||
Searches all fields in a database record including title, abstract, text, etc.
|Results usually relevant to your topic||Results may or may not be relevant to your topic|
|Narrows your search providing fewer results||
Broadens your search providing more results
|Less Flexible - searches only available, pre-defined subject headings||Flexible - searches newer or distinctive terms and acronyms with no defined subject heading|
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To retrieve the best search results when searching library databases, use a combination of both keywords and subject terms.
The following video explains the difference and functionality of both subject terms (controlled vocabulary) and keywords.
Video by Scribner Reference