Boolean logic is a system that allows a searcher to set relationships between keywords or concepts when searching. The most commonly used Boolean commands are AND, OR, and NOT. Parentheses can be used to specify the relationship further. Using these operators can make your searches more precise and save time.
AND NARROWS:
Tells the database that you only want articles that contain ALL of the search terms
smoking AND nicotine
OR EXPANDS:
Tells the database that you want all articles that contain EITHER of the terms
smoking OR nicotine
NOT EXCLUDES:
Tells the database that you do not want any articles that contain a certain term
smoking NOT nicotine
JOINING NARROWS:
Tells the database that you want articles with EITHER of two terms AND another
(smoking OR nicotine) AND cancer
Most databases use the symbol * or # for truncation or wildcard symbols. Use the database's Help tab for verification of the correct symbol.
Truncation Symbol: Uses root of the word…
Example: pharm*
Finds pharmacology, pharmacy, pharmaceutical, etc.
Wildcard Symbol: Allows for multiple spellings of a word...
Example: sul*ur
Finds sulphur and sulfur
Exact Phrase: Use quotation marks to search for an exact phrase.
Example: "persian cat"
Finds information on cats that are the Persian breed, not just cats in relation to anything Persian.
Proximity operators: Proximity (or adjacency) operators allow you to search by phrase or with two or more words in relation to one another. Use the database's Help tab for to verify what symbol to use.
Near (n): if it does not matter which word appears first.
Example: Prozac n3 adverse effects
Finds Prozac within three words of adverse effects
With (w): if your terms must be in the same order in which they are entered.
Example: physical w1 therapy
Finds records where the word physical is listed first, followed by the word therapy, and where no more than one word separates the two terms.
Stop words: Stop words are very common words that are automatically ignored by most databases.
Examples: and, if, or, the, a, for, to, an, as, by
Use quotation marks if you need to search for a term that has a stop word in it, such as "Out of Africa" or "The Who".
Databases usually allow you to limit or filter your search results in various ways. These may include:
