Boolean Searching and Truncation

Boolean Searching

Goerge Booles was a nineteenth century British mathematician. One of his contributions was the developement of Boolean Logic, which defines sets using the terms AND, OR, and NOT (known as Boolean operators). When searching online databases, using these Boolean operators can be of great help in finding information by broadening or narrowing your search to suit your needs. Notice the following examples of Boolean search terms.

The search ...
retrieves ...

tourism AND Mississippi
all records that contain both words. (This narrows the search.)

tourism OR Mississippi
all records that contain either word. (This broadens your search.)

tourism NOT Mississippi
all records with the first term but without the second term. (This narrows your search.)


Suppose you were researching a library-related topic. Some database records may have the term "librarian", but not the term "library". A record could also have the plural of either of those terms. Most databases allow you to search for all variations of a word by using a truncation symbol (usually "*").

Searches for ...

library, libraries, librarian, etc.

engineer, engineers, engineering, etc.

chin, China, Chinese, etc.

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