BOOLEAN SEARCHING

Use "Boolean Searching" when you need more than two words to find results on your topic.

Please see the examples below:

USING "OR"

Use "OR", if you need to obtain more articles. Also, use "OR" for synonyms or different expressions of the topic, as in the examples.

Example of Boolean search	Explanation
euthanasia OR assisted suicide	If your topic is euthanasia, you also need articles on assisted suicide.

Search with subject was used in "PowerSearch" basic search in Gale InfoTrac in LIRN.

Example of Boolean search	Explanation
teenager OR adolescents	If you enter only "teenager," you will miss some articles on adolescents.

Search with subject was used in "PowerSearch" basic search in Gale InfoTrac in LIRN.

USING "AND"

Use "AND", when you have a specific topic to research. Use "AND" when you receive too many irrelevant articles, and you need a smaller number of relevant articles.

Example of Boolean search	Explanation
capital punishment AND cruel and unusual punishment	You are researching to determine whether capital punishment results in cruel and unusual punishment.

Search with subject was used in "PowerSearch" basic search in Gale InfoTrac in LIRN.

Example of Boolean search	Explanation
Internet AND security AND banking	This search limits articles on Internet to security of online banking. The search would be more accurate for your paper.

Search with subject was used in "PowerSearch" basic search in Gale InfoTrac in LIRN.

USING "NOT"

You can sometimes use "NOT" to narrow and define a search better, as in the examples.
It is usually necessary to use the advanced search when using "NOT."

Example of Boolean search	Explanation
Bahamas NOT travel	Suppose you need to research the geography, culture and economy of the Bahamas. Many articles on the "Bahamas" aim to sell travel reservations to the Bahamas, at least on the Internet.

Search with subject was used in "PowerSearch" advanced search in Gale InfoTrac in LIRN.

Most examples were based on an article by Wendy Boswell on Boolean searching, in About.Com.

Which search engines and databases use "Boolean" search terms?

You may perform Boolean searches in the basic search of Gale InfoTrac databases in LIRN, including "AND" "OR" and "NOT."

You can perform Boolean searches in the advanced search in Gale and ProQuest databases in LIRN, ProQuest, and in the advanced search in Ebrary.

With many basic searches, "AND" is accepted or used anyway. If you put two or more search words without "AND" into the search box, the search engine will assume "AND" logic and find only articles with each of your search words.

Advanced search is almost optional to use "AND."

Advanced search is often required to use "OR."

Advanced search is usually required to use "NOT."

If a search engine or database offers "Boolean," consider using it. A complex search can increase the efficiency of your research and actually simplify your life.

A search example is Pregnancy AND (teenagers OR adolescents) AND United States.

The search words are set as subjects (SU) in the drop down menus, and 'United States' is set as a location in the drop down menu, to limit results to this country.

This search obtained a relatively small number of 88 results with relevant articles.

Note: If we had used text or keywords, we would have obtained many more results.

This search was performed in the advanced section in ProQuest in LIRN.

For an example of a boolean search form inside Ebrary, please see the following powerpoint tutorial. The search form is similar to other library databases' forms.

http://www.lac.edu/library/libraryguide/powerpointshows/22searching2.pps

Boolean searching was built on a method of logic designed by George Boole, a 19th century mathematician.

6-01-11