Understanding Boolean Logic is crucial to conducting successful academic research using library resources.

When you search using Google you are using Boolean Logic – even if you don’t know it.

Searching Google for beach vacations has slightly different results from searching “beach vacations” – the quote marks make a difference. 

Google, however, quickly parts ways from Boolean Logic because Google search is predictive; it surfaces results even as you type – guessing (quite accurately) what you are looking for based on what millions of other people have looked for.

You need to be more directive with library databases – stringing together phrases and operators to specify the logic used to search.

Logical operators include the words AND, OR , and NOT. You combine operators with your keywords, sometimes using quotations to indicate phrases, to get relevant results from library databases.

An example would be searching for: policing AND “body cameras” if you were researching criminal justice issues.

Let’s break down how you can use logic to help your searches:

AND

Linking phrases with “AND” will result in matches that feature BOTH words/phrases.

Example: 

  • policing AND “body cameras”

In the Venn Diagram at right, the green represents all the search results that match “policing” and the blue results matching “body cameras.” Because the search includes AND, only the search results in the yellow area would be returned.

OR

Linking phrases with “OR” will result in matches that feature EITHER words/phrases.

Example: 

  • policing OR “body cameras”

In the Venn Diagram at right, the green represents all the search results that match “policing” or “body cameras.” Because the search includes OR, all of the results would would be returned.

NOT

Linking phrases with “NOT” will result in matches that feature just ONE of the words/phrases.

Example: 

  • policing NOT “body cameras”

In the Venn Diagram at right, the blue represents all the search results that match “policing” but NOT “body cameras.” Because the search includes NOT, results with “body cameras” would be excluded.

So you can string together multiple phrases and operators to zoom in on particular research. Example:

policing AND “body cameras” NOT “New York City”

This would begin to get you results concerning police use of body cameras but outside of New York City.