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SHA Library

Boolean Operators

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Keywords

Request an evidence search

The following keyword search tips can be used to refine your search strategies in the medical databases:

(Parentheses):

  • Parentheses can be used to organize (or nest) your keywords into similar concepts by using "OR". Combine searches organized into parentheses with other organized concepts using "AND".
  • Example: (counseling OR therapy OR modality OR intervention) AND (trauma OR PTSD)  

"Phrase Searching":

  • Some databases (including search engines such as Google) enable you to search for concepts as a phrase.  Using quotation marks around search terms is the most common way to conduct phrase searches.
  • Example: "Post-traumatic Stress Disorder"

Truncations: ( * - asterisk)

  • Truncations can be used to broaden your search to include varying word endings or suffixes. 
  • Example: trauma* = trauma or traumas or traumatic or traumatically, etc.

Wildcards: ( ? - question mark ) or ( # hash tag)

  • Wildcards can be used to substitute a symbol for one letter of a word. These commands can be used for words spelled in different ways (i.e. American and British spelling).
  • Example:  p?ediatric = paediatric or pediatric

Adjacency/Proximity: adj3 or N3 or W3

  • Some databases enable you to search for terms and/or phrases with two or more words in relation (and close proximity) to one another. 
  • Example: (teenagers adj3 post-trauma) will retrieve records containing "teenagers" within three words (either before or after) the term "post-trauma"

Note: Refer to the search tips or Help section of each database to see what search functions are available and what each symbol represents. Truncations, wildcards and proximities are usually entered differently depending on what resource you are searching. 

Still not finding what you need? Contact us!

Request an evidence search

The following keyword search tips can be used to refine your search strategies with search engines such as Google:

AND: (not required)

  • Google will automatically search multiple terms using AND. As such, you do not need to use the term AND.
  • Example: counseling trauma = counseling AND trauma

OR: ( | ) 

  • If you want Google to search for terms containing one of several words in your search string, use OR (in all caps) or the pipe (|) symbol.
  • Example:
    • (1) trauma OR PTSD
    • (2) trauma | PTSD

NOT: ( - ) 

  • If you want Google to omit a term/concept from your search, use the minus symbol.
  • Example: trauma -brain = trauma but not traumatic brain injuries

(Parentheses): 

  • Parentheses can be used to organize (or nest) your keywords into similar concepts by using OR.
  • Example: (counseling OR therapy OR modality OR intervention) (trauma OR PTSD)  

"Phrase Searching": 

  • Use quotes around search words to search for an exact phrase.
  • Example:  "borderline personality disorder"

Truncation:

  • Google will automatically truncate your search terms to include varying word endings and suffixes.
  • Example: diet = diets OR dietary OR dieting

site: 

  • This term will restrict your search to a specific (1) top level domain; (2) organization/institution or (3) country.
  • Example:
    • (1) site:.org = (top level domain)
    • (2) site:.site:www.hc-sc.gc.ca = (specific organization/institution) 
    • (3) site:.ca = (specific country)

filetype: 

  • This command will restrict your search to a specific file type.
  • Example:
    • (1) filetype:.pdf = searches PDF files
    • (2) filetype:doc OR filetype:docx OR filetype:rtf OR filetype:odt = searches rich text format
    • (3) filetype:ppt OR filetype:pps OR filetype:pptx OR filetype:odp = searches presentation files
    • (4) filetype:xlsx OR filetype:xls OR filetype:ods = searches spreadsheets
    • (5) filetype:csv OR filetype:txt = searches raw text data

Define: 

  • This command will search for a definition of a term. If you use this command with a colon the search will be restricted to a list of definitions for the term. If the command is used without a colon the search will include both definitions and related pages.
  • Example
    • (1) define:"brief therapy"
    • (2) define "brief therapy"

Related:

  • This command will search for resources related to a particular search result.
  • Example: related:www.cadth.ca

Still not finding what you need? Contact us!

Guidelines Search Tips

About guidelines
  • Also called clinical practice guidelines or practice guidelines
  • Produced by various health-care organizations and professional bodies
  • Can have a local, national or international focus
  • Not useful for finding the latest innovation, practices or evidence
  • Guidelines produced by different organizations may make different recommendations
Where to look
  • DynaMed - summaries include a section on guidelines, with links to specific guidelines
  • Databases - databases such as MEDLINE and CINAHL allow you to limit your search results by guidelines
  • Trip Pro - this clinical search engine allows you to filter your results by guidelines
  • Google - useful for finding guidelines published on individual websites

Still not finding what you need? Contact us!