It’s impossible to get the most out of your search results without combining keywords with Boolean Operators and other search strategies – make sure to read both blog posts!
Many databases require that you combine your keywords using Boolean operators (i.e. “AND” and “OR”) rather than just typing random words like in Google.
For this post, we’ll use the same example from the keywords blog post: I need to find information on the benefits of alternative treatments for type two diabetes (i.e. other than insulin). One of the alternative treatments is managing diabetes with your diet.
We use OR to combine the synonyms that we came up with (because we don’t care which word appears in the text). OR also broadens your search: use different OR words if you aren’t getting enough search results.
We use AND to combine the different concepts from our topic. AND also narrows your search: use a few AND words if you’re getting too many results.
Food and Nutrition Example
“OR” Examples (when you want to tell the database to give you results with either term):
- diabetes mellitus OR type two diabetes
- diet OR nutrition therapy
“AND” Examples (when you want to tell the database to give you results with both terms):
- diabetes AND diet
- diabetes mellitus AND nutrition therapy
Here’s an example of “and” using the library catalogue:
You can combine Boolean Operators too!
(diabetes mellitus OR type two diabetes) AND (diet OR nutrition therapy)
English Literature Example
Search: Shakespeare and satire
“OR” Examples (when you want to tell the database to give you results with either term)
- Shakespearean drama OR Early modern drama
- Satire OR parody
“AND” Examples (when you want to tell the database to give you results with both terms)
- Shakespeare AND satire
- Early modern drama AND comic
Combination Example (when you want to develop a specific, targeted search)
- (Satire OR parody) AND (Shakespearean drama OR Early modern drama)
- Since the above searches both involve multiple words that are meant to be found together (e.g. “diabetes mellitus” and “Shakespearean drama” are meant to be found as a unit rather than two separate words), you can combine them with quotation marks. Other examples: “diet therapy”, “early modern drama”.
- You might also consider using truncation! To ‘truncate’ a word, you replace the ending of a word with an asterisk (*) to allow for multiple endings. So, for the word ‘diabetes’, you might put diabet* – this will allow for endings including diabetes, diabetics, and diabetic to show up in the catalogue.
- To find more strategies like the ones above, you can pick up a hand-out on Boolean Operators and Search Limits at the library.
Knowing how Boolean Operators work (and having some other strategies to use) is a helpful skill, whether you’re searching in academic databases, on government websites, or in the catalogue. Even Google uses them without you even knowing it!
Note: This blog post was adapted from a prior blog post on Boolean operators, developed by Heather Campbell.