Keyword searches work with three basic operators, involving Boolean logic. Boolean operators tell the computer whether you want to:
Today, most databases automatically search for all the keywords you typed (AND), because it's the most common and useful way to narrow a search.
But you may find some advanced search forms will display a choice of operators, so that you can see them work. i.e. JEWL advanced search.
Searching elections AND contributors will find resources with both terms, giving you more specific results.
Searching political action committee OR pac; college OR university, corn OR maize using the OR operator will find resources with either term or both, giving more results.
Searching elections NOT presidential will find resources on elections (local, Senate, etc.) but exclude information about Presidential elections.
Caution: Be careful when using NOT! The term you want may be present in an important way in results that also contain the word you wish to avoid.
A truncation symbol allows you to search for alternative word endings.
EX: politic* searches politic, politics, and political at the same time.
The truncation symbol is often the (*) asterisk. However, some databases use other symbols.
Use the help option in the database or ask a librarian to check on which symbol to use.
You may want to combine the search strategies discussed above. When using a combination of Boolean operators use parentheses to delineate the search.
(PAC OR political action committee) and campaign* and financ*
Note: Some databases create the combining for you when using an advanced search box. i.e. JEWL search has an advanced search box.
If you enter a search such as grade inflation without any Boolean operators, some databases will search for the terms separately. Others will search for the phrase. To guarantee you search for the phrase--the words together in the specified order--use quotation marks.
Credit: This page is adapted from South Dakota State University.
The Boolean Machine is a website with a graphic represenation of AND, OR, NOT. Hover over each one to see how they work.
Colorado State University Libraries has an interactive video Searching Effectively Using AND, OR, NOT.