What Does Boolean Search Really Mean?

Google search engine page
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There are a few basic principles that you can successfully use in nearly all the search engines out there to find exactly what it is that you are looking for, and one of the most basic techniques is using the add and subtract symbols in your web search query. This is commonly known as Boolean search and is one of the most elementary techniques you can use in your search efforts (as well as one of the most successful). These techniques are simple, yet remarkably effective, and they tend to work in nearly all search engines and search directories on the Web. 

What is Boolean Search?

Boolean searches allow you to combine words and phrases using the words AND, OR, NOT and NEAR(otherwise known as Boolean operators) to limit, widen, or define your search. Most Internet search engines and Web directories default to these Boolean search parameters anyway, but a good Web searcher should know how to use basic Boolean operators.

Where does the term Boolean originate?

George Boole, an English mathematician in the 19th century, developed "Boolean Logic" in order to combine certain concepts and exclude certain concepts when searching databases. 

Most online databases and search engines support Boolean searches. Boolean search techniques can be used to carry out effective searches, cutting out many unrelated documents.

Is 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. Boolean logic is just the term used to describe certain logical operations that are used to combine search terms in many search engine databases and directories on the Net. It's not rocket science, but it sure sounds fancy (try throwing this phrase out in common conversation!).

How do I do a Boolean 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 you, the searcher, on which method you're more comfortable with. For example:

Boolean Search Operators

  • The Boolean search operator AND is equal to the "+" symbol.
  • The Boolean search operator NOT is equal to the "-" symbol.
  • The Boolean search operator OR is the default setting of any search engine; meaning, all search engines will return all the words you type in, automatically.
  • The Boolean search operator NEAR is equal to putting a search query in quotes, i.e., "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 - Boolean - Can Help With Your Web Search

Basic math can really help you in your Web search quest. Here's how it works:

  • The minus symbol:

Use the "-" symbol when you want a search engine to find pages that have one search word on them, but you need the search engine to exclude other words commonly associated with that search word. For example:

  • Superman -Krypton

You are telling the search engines that you would like to find pages that only have the words "Superman", but exclude the listings that include information about "Krypton". This is a fast and easy way to eliminate extra information and narrow your search down; plus you can do a string of excluded words, like this: superman -krypton -"lex luthor".

  • The plus symbol:

Now that you know how to eliminate search terms, here's how you can add them in, using the "+" symbol. For example, if you have terms that must be returned in all your search results, you can place the plus symbol in front of the terms that you need to be included, such as:

  • football+nfl

Your search results would now have both these terms included.

More About Boolean

Keep in mind that not all search engines and directories support Boolean terms. However, most do, and you can easily find out if the one you want to use supports this technique by consulting the FAQ's (Frequently Asked Questions) on a search engine or directory's home page.

Pronunciation: BOO-le-un

Also Known As: Boolean, boolean logic, boolean search, boolean operators, boolean operands, boolean definition, boolean searching, boolean commands

Examples: Using AND narrows a search by combining terms; it will retrieve documents that use both the search terms you specify, as in this example:

  • Portland AND Oregon

Using OR broadens a search to include results that contain either of the words you type in.

  • liberal OR democrat

Using NOT will narrow a search by excluding certain search terms.

  • Oregon NOT travel

Boolean Search: Useful for Efficient Searching

Boolean search technology is one of the foundation concepts underneath modern day search engines. Without even realizing it, we are taking advantage of this simple search process almost every time we type in a search query. Understanding the process and knowledge of Boolean searching will give us the necessary expertise we need to make our searches even more efficient.