Boolean Searching

Boolean searching (the name comes from "Boolean algebra") involves the use of words called operators to connect your search words.   The most commonly used operators are the words AND, OR, and NOT.  Boolean searching is used in most library catalogs, including Quest, as well as most electronic periodical indexes.

AND placed between two words requires that both the first word and the second word occur in your search results.  For example, in this Quest search,

k=alcohol and memory

items retrieved by Quest would have both the words "alcohol" and "memory" somewhere in the titles, subject headings, or other fields.  If only one of the words occurs in a record, it won't be retrieved by the software.  The AND operator allows you to narrow a search by requiring that more than one word or concept be present in the resulting items.

OR placed between two words requires that either one word or the other word must occur in the resulting items.  If an item's description includes both words, that also qualifies as a match.

k=woman or women

In this example, Quest would give you a list of books, etc., that contained either the word "woman" or the word "women."  As you can see, using the OR operator allows you to look for synonyms or related terms in one search, rather than requiring you to perform multiple searches for each related term.

NOT placed between two words requires that the first word be found without any occurrence of the second term.  In this example,

k=mexico not new

Quest would retrieve all the records containing the word "mexico," but then it would throw out all those using the term "new."  This would be one method of finding materials on Mexico but avoiding those about "New Mexico."   However, you should be careful with this operator, because you will sometimes exclude items you did not plan to cut out.  For example, the previous search would have excluded a book with the title, "New Perspectives on the History of Mexico."  Think carefully about what will be excluded before you use this connector!

Combining Operators

Boolean operators can be used more than once or combined in a search statement.   Parentheses are often used to tell the online system the order in which you'd like the operations performed (just as you use them in math when mixing addition and multiplication operators, for instance).

k=(woman or women) and religion

searches for either of the first words, then requires that any records with one of those terms must also have the word "religion;"

k=(behavior or behaviour) and (rats or mice or rodents)

allows one to search for variant spellings of the first concept and combine that with any one in a series of related terms.

Because most library catalogs and many periodical indexes have only a small number of terms in their records, it is usually wise to select no more than three or four terms that must occur in a search result (that is, terms that are connected by AND).   If your search ends up with no results, you should re-try your search with fewer required terms.

Read about Relevancy Searching