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Discovery how-to guide

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What are Boolean Operators/Commands?

Boolean searching is a method of combining keywords/concepts using the following three words to improve the relevancy and precision of search results in a search engine. 

AND  -  NOT  -  OR 

Catalogues, databases, and online search tools utilise this method. In academic search engines like Discovery, these are not simply words but logical commands, and each has its distinctive function. 

Boolean operator ANDAND 

AND operator narrows your search and returns fewer results. In a search where you would like to find sources that cover multiple concepts, you should use AND. For example,  Leadership AND Social Work (see image) combined in the same search using AND. In theory, this should return results that mention both Leadership plus Social Work. For instance, if a paper mentions only Leadership but not Social Work, it will not appear in your search results. 


Boolean -OROR operator broadens your search and returns more results. Using OR you can connect two or more similar concepts. You could connect similar terms, those could be: 

  • Synonyms
  • Alternative spellings 
  • Broader terms 
  • Narrower terms

In the example displayed on the right Higher Education combined with University using OR operator. This means they both have equal value and your search could return papers that has mention of one or the other or both.


NOT operator narrows your search and returns fewer results. In a search where you would like to exclude sources which have a mention of a term in relation to another, you could use NOT. For example, Social media NOT Facebook. 





Use of Boolean Operators/Commands in Discovery

In Discovery Search, Boolean Operators are placed on the left side of the search box in a dropdown menu where you can choose the appropriate one. The general practice is to select "AND" on the dropdown menu and manually type the "OR" operator in the search boxes. This way, you can connect your different concepts using AND (as each line will have words related to a single concepts) in between each line and add your alternative terms in the line by adding OR in between each synonym or terms. See the example in the image below: 

Boolean operators must be typed in upper case (capital) letters when typed in the search box.

boolean operators