Becoming a Better Searcher: Using Boolean Operators to Find Stuff Faster

Searching is easy, right? You just punch a bunch of words in that have to do with your topic and hope to get results. If you do not get results, then you try some different words. Eventually you will find that information. Not so fast! What you are doing is going to get you results eventually, but you are not using the most powerful tool in the searcher’s arsenal: Boolean operators. This post explains what Boolean operators are and how to exploit their potential.

AND, OR, NOT

Boolean operators exploit a type of logical arithmetic invented by George Boole in the mid nineteenth
century.  Boolean Algebra, as it came to be called, allows a person to express a complex series of statements or propositions as a mathematical function. In our case, that means that instead of asking for just one criterion to be satisfied in a search engine query, the searcher can ask for multiple things using the following logical expressions:


  • AND—The first expression is the simplest, “AND.” Using an “AND” operator means that multiple conditions must be satisfied to return a result. This is the default way that a search engine works (implied AND). If you type in chicken finger for your query, the search engine will not return a result unless it contains the word “chicken” and the word “finger.”
  • OR—The “OR” operator returns results if they satisfy at least one of multiple results. If you search chicken OR finger, the search engine will return all results that have either or both of those words in them.
  • NOT—The “NOT” operator tells the search engine to return only results that do not satisfy a certain criterion. Searching for chicken NOT finger will return only results that do have the word “chicken” but do not have the word “finger.”


How do I do this?

All of that is a lot of words, but it is probably unclear how you actually use this right now. Not to worry!  Let us look at how these queries are constructed.

We already know how to search for a simple two word query, which has an implied AND: chicken finger. But suppose you want to expand this to people who might call chicken fingers something else. You could search for chicken finger OR thumbs.

But suppose you want to go ever farther. You cannot just append another OR. Here we add in parentheses. Parentheses can contain any logical expression, which can be either a single unit (chicken) or a whole complex query in and of itself (finger OR thumbs).

In our case, we want to expand our search to collect more results, so we will add another possible name for the food item: chicken AND (fingers OR thumbs OR strips). If we really have a hankering for poultry, we could even add more ingredients to the first part of the query: (chicken OR turkey) AND (fingers or thumbs OR strips). Or we could remove ingredients that we do not want: (chicken OR turkey NOT fish) AND (fingers OR thumbs OR strips). Now we get results about chicken fingers but not fish fingers.


In this way, queries can be expanded infinitely, narrowing down results to only the most relevant to your information needs or expanding the scope of your search to collect more results. Note that based on the search engine, the exact syntax may change. For example, Google uses the minus sign (-) instead of the word NOT.

Boolean searching is a very powerful tool that the serious searcher should not overlook. It can allow a user The ExtremeSearcher's Internet Handbook : A Guide for the Serious Searcher, available in our catalog.
to more quickly find relevant results and is almost universally implemented today, making it a critical tool to know. For more on this topic, you might want to read

- Ross H.
Boole photo courtesy of WikimediaCommons

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