What Is a Boolean Search?

Google search engine page
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There are a few basic techniques that you can use in nearly all the search engines out there to find exactly what you're looking for — and they work because most search engines recognize Boolean (pronounced BOO-le-un) search operators. Boolean searches are simple, yet remarkably effective, and they tend to work in nearly all search engines and search directories on the Web. 

What Is a Boolean Search?

Boolean searches allow you to combine words and phrases using the words AND, OR, NOT and NEAR, along with the add and subtract symbols. These are known as Boolean operators, and you can use them to limit, widen, or define your search. Most internet search engines and Web directories default to these Boolean search parameters anyway, but knowing how to use these operators can make your searches more efficient, convenient, and successful.

Where Does the Term Boolean Originate?

George Boole, an English mathematician in the 19th century, developed an algebraic method that he first described in his 1847 book, "The Mathematical Analysis of Logic", and expounded upon in his "An Investigation of the Laws of Thought" (1854). Boolean algebra is fundamental to modern computing, and all major programming languages include it. It also figures heavily in statistical methods and set theory.

Today's database searches are largely based on Boolean logic, which allows us to specify parameters in detail — for instance, combining terms to include while excluding others. Given that the internet is akin to a vast collection of information databases, Boolean concepts apply here as well.

Is a Boolean Search Complicated?

Using Boolean logic to broaden and/or narrow your search is not as complicated as it sounds; in fact, you might already be doing it. A Boolean search simply entails certain logical operations to combine search terms. It's not rocket science, although it sounds it (try throwing this phrase out in common conversation!).

How to Perform a Boolean Search

To use Boolean concepts in a search, you have two choices: You can use the standard Boolean operators (AND, OR, NOT, or NEAR, or you can use their math equivalents. It depends on your preferences and what you're most comfortable with.

Boolean Search Operators

For the purposes of an internet search, here are the terms and symbols you need to know:

  • The Boolean search operator AND is equal to the + (plus) symbol.
  • The Boolean search operator NOT is equal to the - (minus) symbol.
  • The Boolean search operator OR is the default setting of any search engine — meaning, all search engines will return matches for any of the words you enter.
  • The Boolean search operator NEAR is equal to putting a search query in quotes, e.g., "sponge bob squarepants." You're essentially telling the search engine that you want all of these words, in this specific order or this specific phrase.

Basic Math Can Help With Your Web Search

Believe it or not, basic math can help you with web searches. Here's how:

  • The minus symbol: Use the - symbol when you want a search engine to exclude the term immediately following it. For example, if you search for Superman -Krypton, you are telling the search engines to find pages that include "Superman," but not "Krypton." Using the minus symbol to mean "not" is a fast and easy way to eliminate extra information and narrow your search down.
  • The plus symbol: Now that you know how to eliminate search terms, here's how you can add them using the + symbol. To specify terms that must be returned in all your search results, place the plus symbol in front of the relevant term. For example, football+nfl will produce results that include both these words. Conversely, entering football nfl in the search box will return pages that include one word or the other, or both. Remember, the plus symbol means "and."
  • You can combine operators, too, for more complicated, targeted searches. For example, you could enter superman -krypton -"lex luthor" to find pages that include "superman" but neither "krypton" nor the entire phrase "lex luthor."

    More About Boolean

    Keep in mind that some less prominent search engines and directories might not support Boolean terms. Just consult the search engine's FAQs (frequently asked questions) on in its support area.

    Without even realizing it, you are taking advantage of this simple search methodology almost every time you type in a search query. Understanding the fundamentals of Boolean searching can help you find exactly what you need fast.