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Search effectively

Boolean operators: AND & OR




Use the interactive activity below to discover how AND/OR searching works. Keep scrolling for more information on using Boolean operators in your searching.

1. OR Searching

Find search results which contain any of your search terms. Type OR in upper case letters between each of your synonyms. This will retrieve results which include at least one if not both of the words.

For Example:
teenagers OR adolescents
migraine OR vascular headache


2. AND Searching

Find search results which contain all of your search terms. Use the AND between your concepts to ensure that each search result includes all of the words in the same book or article record.

For Example:
teenagers AND migraine AND diet


3. Combining AND & OR Searching

Combine all of your concepts and synonyms in one search by using round brackets to separate the ORs from the ANDs. This is similar to algebra. In the example below I have also applied truncation and phrase searching where appropriate.

For Example:
(diet* OR nutrition OR "food intake") AND (migraine OR "vascular headache") AND (teen* OR adolescen*)

This search strategy will retrieve results that include at least one of the terms from each category. Brackets have been placed strategically to separate the ANDs from the ORs (a bit like algebra).