Boolean

Boolean Searching

“Boolean search” (named after Irish mathematician George Boole) is an effective way to search using three special terms:

A typical research question might be phrased “How do images in the media cause eating disorders in women and teenage girls?”

Break down the question into a list of important words and phrases.

Concept Synonyms
mass media movies, television, magazines
eating disorders anorexia, bulimia
girls females, women

Boolean And

Venn diagram, showing area matching body image and eathing disorders search terms
body image AND eating disorders

Boolean and narrows a search to those items containing both terms (represented by the darkest area in the diagram). The results list would consist of only items which have both terms: items which mention only body image will not be displayed, nor will items which mention only eating disorders without reference to body image.

You can combine multiple words and phrases in a Boolean search. For example:

"advertising AND body image AND eating disorders AND teenage girls"

The more words you combine with Boolean and, the fewer results you will get.

Boolean Or

anorexia OR eating disorders
Venn diagram showing union of anorexia and eating disorder search terms

Boolean or broadens a search by looking for items containing at least one of the terms. The above search would result in items about anorexia, items about eating disorders, and items about both anorexia and eating disorders.

Use or if you have synonyms or words with various spellings.

Examples:

  • “gangster or gangsta”
  • “genetically modified foods or GMO or genetically modified organisms or frankenfoods”
  • “pets or dogs or cats or birds or reptiles”
  • “teenage or adolescent”

Boolean Not

Venn diagram showing results for solution search, excluding chemistry

Boolean not excludes terms from a search. It can be used to exclude different meanings of the same word, as in the diagram above. It can also be used to exclude different aspects of your topic, e.g. fish not freshwater.

Use not with great care - it may exclude results that have information on your topic. For example, if an article is mostly about saltwater fish but includes the sentence, “This paper will not discuss freshwater fish” a Boolean not search will not show this result even though it is all about saltwater fish because the word “freshwater” appeared once.

Check out this YouTube video (3:11) on how to use Boolean Searching in EBSCOhost.