Combine keywords

To better search the library databases and the library catalogue you need to create search statements using your keywords and Boolean operators. Boolean operators are words that connect your keywords.


Posted with permission of Douglas College library.

Some information also available on ProQuest training tools.


OR combines your synonyms and related terms to find documents that contain >strong>any or all of the words. It broadens your search and produces more results.

Example: light bulb OR green


AND combines your different concepts to find only the documents that contain all of the keywords. It narrows your search and produces fewer results.

Example: light bulb AND green


NOT followed by a keyword will exclude all the documents that contain that particular word. It is a way of avoiding unrelated articles. Use it with caution as you may miss out on potentially useful material.

Example: drugs NOT heroin