Using AND, OR, and NOT to connect your search terms together will help you find exactly what you're looking for. These words, known as Boolean operators, tell a database how you want your search terms to relate to each other.
Once you understand how AND, OR, and NOT impact your search, be sure to continue to the next tab of this guide.
Use AND in a search to:
Example: cloning AND humans AND ethics.
In the image below, the center of the Venn diagram where the 3 circles overlap (shaded area) represents the results for this search. All results would contain the words cloning, ethics, and humans.
Many library databases automatically search with AND between search terms unless you specify otherwise -- just like Google.
Use OR in a search to:
Example: teacher OR instructor OR professor.
As demonstrated in the image below, your results could come from any of the circles in the Venn diagram (all areas are shaded). Each result will contain one or more of your terms: teacher, instructor, or professor.
Use NOT in a search to:
Example: Apple NOT fruit (if trying to find information on the company rather than the fruit).
As demonstrated in the Venn diagram below, your results would include only the part of the Apple circle that does not overlap with the fruit circle.
Beware! Using NOT can exclude potentially useful results so use it carefully. If you're having trouble, ask a librarian.
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