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Finding Academic Sources

Boolean: What it Means & How it Can Help 

Boolean operators are small words (AND, OR, NOT) that can add a lot to your research. These three words used with your keywords can help narrow, broaden, and focus your results.

AND: By adding AND to your keywords, you are limiting your results by telling the database that you want to narrow your research. Results will include both key terms. Say this is your research question, How does the amount of rain affect deforestation in Brazil? Pull out the key terms rainfalldeforestation, and Brazil. Now you enter these into a search by adding the Boolean operator: rainfall AND deforestation AND Brazil. The more you include AND, you will have fewer results returned. 

OR: Including OR into your search terms expands your search results -- casting a wider net for resources you want to see. If your research question is Are teens who spend time on social media more depressed? pull out the key terms teenssocial mediadepressed. But maybe you're also wanting to see results that include synonyms. Your search may look like teens OR teenagers OR adolescent

NOT: The Boolean operator NOT will also limit the results returned. It should be used sparingly. If your research question is exploring the effects of pollutants on Mexico but your results keep coming back with results on Mexico City, your search will look like pollutants AND Mexico NOT city. As this example shows, any of the Boolean operators can be combined to further refine your search. 

For more examples, watch this YouTube Video from How Library Stuff Works.