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Nursing - Information Literacy

Boolean searching

Understanding "Boolean" connectors is fundamental to database searching!

Boolean logic uses the operators AND and OR to connect search terms when using catalogs, databases, or a web search tool.

  • A simple search on: handwashing retrieves ALL article citations containing that term.
  • A search using AND retrieves citations with BOTH terms, e.g.: handwashing AND cross infection.
     
  • OR is used to connect synonyms. A search using OR retrieves citations with ANY of search terms present,
    e.g.: (cross infection OR nosocomial infection OR hospital acquired infection).

A research question with a Problem AND Intervention: Does handwashing among healthcare workers reduce hospital-acquired infection?  

Combine the two terms with AND for a preliminary literature search.

BOOLEAN
OPERATOR     		SEARCH STATEMENT RETRIEVES  

AND

hospital acquired infection

AND

handwashing

Retrieves citations with BOTH terms present
OR

hospital acquired infection
OR
cross infection
OR
nosocomial infection
 

Retrieves citations with EITHER/ANY of the terms present

 

(OR is used to string synonyms together; remember, OR retrieves MORE!)
AND, OR 

(cross infection
OR
nosocomial infection
OR
hospital acquired infection)

AND

handwashing
 

 

 Search sets may be combined. This search locates citations with the word handwashing AND (ANY one of the terms combined with OR)
AND, OR

(cross infection
OR
nosocomial infection
OR
hospital acquired infection)

AND

handwashing

AND

Publication type: randomized controlled trial

Retrieves citations with the word handwashing AND (ANY one of the terms combined with OR) AND limited to articles with the Publication type: randomized controlled trial.

(This is one example of using database Limits.)
NOT

handwashing

NOT

masks

Retrieves citations with the term handwashing, but omits records with the term masks

(Caution: the NOT operator should be used sparingly and carefully as it may omit citations relevant to a search.  

For example, an article about handwashing that includes the word masks might be relevant to a search on handwashing.)