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How to Search


What is Boolean Language?

Boolean search terms ("operators") are simple words that allow a user to expand or narrow a particular search in a search engine. Simple words like AND, OR, and NOT have been created to talk to the databases and allow a user to enter multiple terms to search for in a meaningful way. Many common search engines use Boolean logic, and many of the MBI databases use this same language. The following information is meant to help MBI users understand how these search terms work and what type of returns they will create.


AND Operator

The AND operator retrieves only records that have all the search terms included in the record. Use this operator to narrow or limit a search.

If you type:

The search engine will return:

God AND creation

only records containing both God and creation.

theology AND God AND church

only records that contain all three search terms.


OR Operator

The OR operator retrieves all records that contain one or both of the search terms. Use this operator to expand a search.

If you type:

The search engine will return:

God OR creation

records containing God, records containing creation, and records containing both God and creation.

theology OR God OR church

records containing theology, records containing God, records containing church, records containing any combination of two or all three search terms.


NOT Operator

The NOT operator eliminates records that contain specific search terms. Use this operator to limit a search; however, be careful! You may unintentionally eliminate results from your search that may be useful.

If you type:

The search engine will return:

God NOT creation

records containing the search term God, but with no reference to the term creation.

theology AND God NOT church

records containing the terms theology and God, but with no reference to the term church.


Wildcards and Truncation

Wildcards are used when you are unsure of a particular spelling or if there are alternate spellings of your search term. The most common wildcard symbol across databases is the "?". The wildcards work a little differently within each database, but the common function looks something like this:

If you type:

The database will return:


records containing color, colour, colonizer, and colorimeter.

Similar to wildcards is the truncation function. Truncation is also used when you are unsure of a spelling or only know part of a search term. The common truncation symbol across the databases is the "*". The * returns searches of any words that begin with the letters you've typed, but may end in many different ways. It looks something like this:

If you type:

The database will return:


records containing women, woman, womanizer, women's, etc.


records containing teach, teacher, teachers, teaches, teaching, teachability, etc.


Nesting Functions

The function of nesting is similar to mathematics when dealing with parentheses. In math, you always perform the function within the parentheses, then use that value to determine the equation reading from left to right. Nesting is much the same—you can place a search within parentheses, and the search engine will complete that search, then take the results and combine them with other search terms. Without parentheses, a search will be performed from left to right in order. Not all search engines support nesting the same; however, generally speaking, a nesting function works like this, using FirstSearch as an example:*

If you type:

FirstSearch searches for:

brewers AND baseball OR twins

records containing both baseball and brewers, then records containing twins, whether or not they contain baseball or brewers.

(baseball AND brewers) OR twins

the same results as above because the parentheses group baseball and brewers first in left-to-right order.

baseball AND (brewers OR twins)

records containing either brewers or twins or both; from this set of records, it then searches for records that contain baseball so that all records contain either brewers and baseball or twins and baseball or brewers and twins and baseball.

*cited from FirstSearch Help section (2003)

Using nesting in this way can certainly help you get a little closer to helpful results in a more timely manner, ignoring unnecessary or unhelpful citations.

Now that we've narrowed our search down to what we feel may be useful, we need to know how to interpret and understand the results we're looking at.