ENGL 2130 - Johnston - Spring 2025

They may sound "scary", but Boolean Operators can be your best friend when doing research. You use the words AND, OR, and NOT to combine keywords in specific ways, helping you focus your search in a way simple keywords can't.

The Boolean operators AND, OR, and NOT are often used to combine keywords when searching Galileo. Use of these operators can make your search more focused, thus yielding better search results. But before using the operators, it's necessary to understand how they actually work.

Say you're searching for information on Rock and Roll music. You've determined that your keywords are ROCK and ROLL. 

If you use AND, written ROCK AND ROLL, you get only articles that have BOTH the words ROCK and ROLL. This Venn diagram shows you the two keywords, each in a circle, and in the center the overlap where you would find all those articles.

This is a great search if you're looking for articles on rock and roll music!

This is a very narrow, or very focused search.

If you use OR, written ROCK OR ROLL, you get all the articles that contain either one of your keywords. The diagram shows both circles completely shaded in, which means you'll find everything!

So you *might" get articles about rock and roll music, but they may be buried by other articles like how to bake rolls or building a rock garden!

Another strategy here is to use your synonyms ... maybe your search could look like MUSIC (ROCK OR POP). So now I can find articles about both rock and pop music!

If you use NOT, written ROLL NOT ROCK in this case, you will locate articles that do not have the word you set apart with NOT. So in the diagram, we are *excluding* ROCK from our search. This is great when you need to eliminate some keyword that keeps coming up even though it's off topic.

Keep in mind that  AND and NOT generally limit your search (decreases the number of results) and OR expands it (increases the number of results). So the following strategies naturally follow:

• If you are retrieving too many records on your topic, try adding another keyword with the connector AND.
• If you are retrieving too many records on an unrelated topic, try eliminating a word with the connector NOT
• If you are retrieving too few records on your topic, try adding another keyword with the connector OR.