Boolean Operators
One of the easiest ways to refine your search is to use the Boolean operators. The three most common Boolean operators are AND, OR, and NOT, but there are others available. The operators AND and NOT will narrow your search and OR will usually increase your search results. (The AND operator is not necessary in Google; Google automatically adds the AND between words unless a phrase is put in quotation marks.)
The chart below explains differences between the Boolean operators.
Boolean operator
|
Function
|
Example
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AND
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· Narrows search result
· Finds articles/websites with both terms in them. Terms may not necessarily be next to each other
|
"global warming" AND hurricane* (retrieves articles with both terms)
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OR
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· Broadens search result
· Use to combine similar terms. One or the other search term must appear in the article/website
· Put parentheses around your ORs
|
"global warming" OR "greenhouse effect" (retrieves articles with either term)
|
NOT
|
· Narrows search result
· Use to eliminate terms from search
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"global warming" NOT Antarctica (eliminates articles that have the word Antarctica in them)
|
Phrase searching
Most of the databases and search engines will AND the words of a phrase together. If you wish to search the term as a phrase, put quotation marks around it to refine your search.
identity theft = identity AND theft
“identity theft” keeps the words of the phrase together
Truncation
Most databases use the asterisk * to truncate words. For example, child* will search for the words child or child’s or children. Another example is listed below.
develop* = develop + develops + development + developmental
Google automatically looks for the singular and plural of a word.
Combining some of the skills together
Some examples:
(dog OR dogs OR canine*) AND (kennel* OR board*) AND “port huron”
(ipad OR tablet) AND (evaluat* OR review*)