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Cochrane Library (English): Searching Techniques

Searching Techniques

This page lists different search techniques you can use: boolean search, exact search, masking and tuncation.

Boolean Searching

Boolean searching means using ANDOR or NOT when searching. Cochrane also allows the use of the NEAR and NEXT operators. These are the so called proximity operators.

► With AND, you search for sources that contain both terms.
OR searches for sources containing at least one of the search terms.
NOT indicates which word Cochrane should not search for.
► NEAR indicates that 6 words is the maximum distance between two search terms. These search terms do not have to appear in the same order. Use /X to customize the maximum word distance.
► Use NEXT to indicate that two search terms have to appear next to each other and in the same order.

Examples: Boolean Searching

You look for articles that contain different combinations of search terms.

► Child AND "hearing disorder"
Child OR "young patient"
► Child 
NOT baby
► Child 
NEAR "behavioral therapy" (or: NEAR/9)
► Child* NEXT health

Exact Search

Using double quotation marks (". . .") you can make an exact search

► This means that you search literally for the word combination between the inverted commas.
► This prevents the words between inverted commas from being searched as separate terms.

Examples: Exact Searching

You look for sources in which the search terms appear in that exact order and proximity.

► Use "Hearing disorderto avoid looking up Hearing and Disorder as separate keywords.
► Use "Auditory-verbal therapy for promoting spoken language development in children with permanent hearing impairments" to look up this specific article (= title).


Masking means concealing something, e.g. that you don't feel sure about it. Masking is done with an asterisk / * or question mark / ? in the middle of a word.

► Use this search technique if you are not sure of the spelling.
► Use this search technique if you want to search for multiple spelling options (e.g. American and British English).

Examples: Masking

You let the search engine fill a certain part of a word.

► Search Behavio*to search for Behavior and Behaviour.
► Search Drug? if you want to search singular and plural simultaneously (Drug or Drugs). 


Truncation means leaving out part of the word. In Cochrane, this works with an asterisk (one or more characters) or question mark (one character). 

► Search with an asterisk or wildcard to break down a word from a specific place and automatically search for all possible endings.

Examples: Truncation

You want to return part of a word anyway and let the search engine search with all possible outputs.

► Use Therap* to search for TherapeuticTherapiesTherapy ...
► Use *tension to search for HypertensionHypotension ...
► Use P*ediatrics to search for Paediatrics en Pediatrics | Disclaimer | Over Zuyd Bibliotheek