Research Guides: Boolean Operators: A Cheat Sheet: Home (2024)

FAQs

What are the Boolean operators in research? ›

Boolean Operators are simple words (AND, OR, NOT or AND NOT) used as conjunctions to combine or exclude keywords in a search, resulting in more focused and productive results. This should save time and effort by eliminating inappropriate hits that must be scanned before discarding.

The Boolean data type can only represent two values: true or false. Boolean expressions are expressions in a programming language that produce a Boolean value. This is like asking a question where the logical answers can only be true or false.

Google no longer accepts the use of all Boolean modifiers and operators, so check this page to find out which ones you can use in Google! This guide on Boolean Searching by the Elmer F. Rasmusen Library visualizes Boolean Logic searching using Venn diagrams.

Boolean operators are the words "AND", "OR" and "NOT". When used in library databases (typed between your keywords) they can make each search more precise - and save you time!

The most popular Boolean commands are AND, OR, and NOT. Other commands include parentheses, truncation, and phrases.

Boolean logic is a type of algebra in which results are calculated as either TRUE or FALSE (known as truth values or truth variables). Instead of using arithmetic operators like addition, subtraction, and multiplication, Boolean logic utilizes three basic logical operators: AND, OR, and NOT.

Boolean logic refers to the logical relationship among search terms, and is named for the British-born Irish mathematician George Boole. Boolean logic consists of three primary logical operators: OR, AND, and NOT. Each operator can be visually described by using Venn diagrams, as shown below.

The asterisk serves as the truncation (or wildcard) operator. Unlike the other operators, it should be appended to the word to be affected. Words match if they begin with the word preceding the * operator.

The default and “hidden” Boolean operator in a standard Google search is: AND. OR.

What happens when you add not to your search phrase? ›

Use NOT to narrow your search. Using NOT narrows your search as it instructs the database to ignore results that contain particular words. - will return results that include social media, but do not include Twitter. NOT tends to be used less than the And and OR operators.

Using AND, OR, and NOT to Refine your Keyword Search

In a Boolean search, keywords are combined by the operators AND, OR and NOT to narrow or broaden the search (you do not have to enter them in capitals).

Boolean Operator - NOT

Use NOT to exclude words or phrases from your search. NOT must be capitalized and can be used multiple times within a search.

Boolean logic defines logical relationships between terms in a search. The Boolean search operators are and, or and not. You can use these operators to create a very broad or very narrow search. And combines search terms so that each search result contains all of the terms.

Boolean operators: AND, OR, and NOT, must be entered in UPPERCASE. PubMed processes Boolean connectors in a left-to-right sequence. You can change the order in which PubMed processes a search statement by enclosing, that is nesting, an individual concept in parentheses.

The three most commonly used operators are AND, OR, NOT. These are known as Boolean operators. They can be used to broaden or narrow a search and to exclude unwanted search terms and concepts.

Boolean Operators link concepts and are used to broaden or narrow your search. AND - finds results with your all search terms. AND narrows your search. OR - finds results with any of your search terms.