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Occupational Therapy - Dallas

Occupational therapy research guide for TWU Dallas students, faculty and staff.

Boolean operators

There are three Boolean operators: AND, OR, & NOT.


The AND Boolean operator will reduce the amount of results a search yields as it forces the database to be more specific. For example, here the database will only return results that feature both the terms "peanut butter" AND jelly.

TIP* If you have too many results to wade through...try using an additional search concept with AND to get a smaller, more specific, batch of results.

               AND boolean operator


OR is used to adding synonyms or alternate words to your search. By adding more synonyms to each concept you should get more results. A good rule of thumb is that OR is always more.

Here you can see that the database will bring back all articles that have either the phrase "peanut butter", or the word jelly, or both.

            OR boolean operator


The NOT  Boolean operator will purposefully exclude articles containing the specified search term/s. 

NOT can be used to narrow down the desired meaning of a term that has different connotative meanings. 

Use the NOT Boolean operator with care. You might lose the perfect article because it randomly mentioned the term you excluded. If you need to reduce the amount of results your search yields first try thinking of another search term and adding it to your search with an AND.

                            Not boolean operator

Here you can see that the database will bring back articles about "peanut butter"-- but if that article mentions jelly anywhere in the text, even randomly, the database will exclude that article from the results.