What's in this article:
- How to use Boolean logic to narrow your search more precisely
- Using the AND operator
- Using the OR operator
- Usinge the NOT operator
There comes a time in the life of every researcher when they hit a wall in their efforts to find relevant content. Your academic quiver might be full of exact phrases and fielded searching, but you just can’t seem to get to the good stuff that will help you advance your argument or support your esoteric assertions. If you find yourself in this common plight, you really can’t go wrong by reaching out to a librarian AKA the gatekeepers of knowledge.
However, with a little practice you can also employ a librarian’s secret weapon yourself with a minimum of fuss. The weapon is Boolean Searching and it is mainly comprised of three parts, just like Charlie’s Angels, or the Deathly Hallows.
These parts are called Boolean Operators and they are as follows: AND, OR, and NOT. Boolean operators are used to connect your search terms, and can be used to either narrow or broaden your search results.
This is the default Boolean operator, and using it will narrow your search results by telling the search engine to return results that have BOTH/ALL search terms present.
When we search JSTOR for scholarly content about unicorns, we get a very large set of results.
Suppose a scholar is specifically researching the claim that unicorns appear to maidens. In that case, refining this set of results by adding the term “maiden” will decrease the number of results they have to sift through to find that perfect article.
All 119 results will include both the term “unicorns” and the term “maidens.” Thanks, Boolean operator AND!
Using this Boolean operator will expand your search results by telling the search engine to return results that have EITHER/ANY of the search terms present.
This same unicorn researcher did not find exactly what they were looking for just by using the AND operator. One strategy that a librarian would employ in such a case is to use the OR operator to link synonym keywords together and expand the search results.
This unicorn researcher now has a slightly expanded list of results to peruse. Even for researchers in non-unicorn disciplines, the OR operator is a great chance to use all the jargon your heart desires. If a term is a synonym, throw it in your query and see what happens!
An important note here about using parentheses: When your search query includes multiple Boolean operators, it is important to group them appropriately. In the example above, (maiden OR virgin) is grouped together by parentheses, making it a sub-query. By grouping the terms this way, you are telling the search engine what terms must be present and what terms are optional. This eliminates any confusion and ensures that unicorns must exist and that either term maidens or virgins may exist.
Using this Boolean operator will narrow your search results by telling the search engine to exclude results that have a particular search term present.
Our brave researcher is just plain tired of trying to find relevant results for his thesis and coming across close-minded papers claiming that unicorns are mythical creatures. In this scenario, he can employ the NOT operator to exclude this nonsense from his search results.
This set of results is smaller than the previous one, and no longer includes any content with that offensive word “myth.” Finally our researcher finds the right content for his thesis and can get back to his field work, and it’s all thanks to Boolean searching!
The beauty of Boolean searching is that these operators can be mixed and matched in any number of ways in an attempt to drill down and find that paper you didn’t even know you needed. They are also filters you can employ as part of your living, breathing searching habits. If you see that a set of search results has a specific vein of noise, you can adjust your query with the NOT operator. If you just learned a synonym for one of your keywords, you can expand your results with the OR operator. Boolean logic also plays nicely with the other tools in your research arsenal, like exact phrase and fielded searching. The research possibilities are endless.
So let’s take a moment to appreciate George Boole, the man behind the logic that makes targeted searching such a breeze for folks in the know:
When all else fails, always ask a librarian for help! They are trained Boolean ninjas, but totally don’t be scared of them! They are awesome and love to help.