Boolean terms (sometimes called Boolean operators or command terms) connect your keywords to create a logical phrase that the database can understand. This may involve telling the database to look for multiple terms or concepts at once, which will make your search more precise. Or it may involve searching for alternative terms that will bring back more results.
Using Boolean terms helps to create more precise and powerful searches with a higher percentage of relevant results.
This page will show you how to use the Boolean terms AND, OR, and NOT in your searches.
Boolean terms: AND, OR, NOT
|Boolean Term||What it Does||How to Use|
|AND||Find items that use BOTH keywords.||adult learning AND online courses|
|OR||Find items that use EITHER of the keywords.||adult learners OR adult students|
|NOT||EXCLUDES items that use the keyword(s).||NOT masters programs|
Note: You do not have to capitalize and, or, and not in your searches.
The AND operator:
- connects different concepts
- limits your search
- reduces results
school leadership AND at risk students AND academic progress
Finds articles that have information about all three of these topics.
The OR operator:
- finds different ways to phrase a concept
- expands your search
- increases results
school leadership OR at risk students OR academic progress
Finds articles that may talk about any one of these topics (does not have to include them all).
The NOT operator:
- excludes results with the keyword
- reduces results
at risk students NOT school leadership
Takes out articles with the term used with NOT.
WARNING: Use NOT with caution. It can remove relevant results.
Truncate root words
Truncation allows you to search any ending on a root word.
For example, if your topic uses the word teenagers, then you may also want to search:
The root word is teen. To truncate and search teen with any ending you would enter:
The asterisk at the end of the root word tells the database to search for that word with any ending.
This expands your search to find more articles.
Use Boolean terms
Type in one concept per search box.
The advanced search in most databases defaults to automatically use AND between the search boxes. Leave the default. The database will find articles that include both concepts.
Use OR inside the search boxes to add synonyms or related terms to the search. Because the database will only search for the exact terms entered, using OR helps find the different ways an author may have phrased the concept.
For best results, only use the OR within a search box. The AND is placed automatically between the search boxes.
An example search for violence on television using boolean terms might look like this:
First search box: TV or television or mass media
Second search box: violence or aggression