ERIC Tutorial

4.2 Advanced Strategy: More on Boolean Searching

This is a very useful search strategy with a very odd name! The mathematician George Boole (hence the name) developed ways to combine search terms for more precise searching. The key is to understand the ways in which you can combine your terms.

Imagine that you have a class full of students, some of whom have brown eyes. Some of your students also wear glasses. If you asked to meet with all the students who have "brown eyes AND glasses", you want only students satisfying both criteria. In the same way, when you do a search for articles about "portfolio assessment" AND "mathematics" you are looking for results that are about BOTH subjects. You are adding another requirement. You will also be getting a smaller set of results each time you add another term.

Image of two circles overlapping each other, the area that they overlap  represents the results of an AND search.

Now let's suppose you are not getting enough articles about "portfolio assessment," and want to try some related terms you found in the Thesaurus. This is where OR is useful! For example, you may want to expand your searching to "portfolio assessment" OR "portfolios (background materials)" - which will give you results about either of these topics.

Image of two circles overlapping each other, the area that they overlap  represents the results of an OR search.

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