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How to Research Guide

DU Libraries

Primary & Secondary Sources

A primary source is an original document/image, the results of an experiment, statistical data, first-hand account, or creative work.  A secondary source is something written about or using primary sources.

Examples of Primary and Secondary Sources

Primary Secondary
The text of The Gettysburg Address An analysis of The Gettysburg Address
Census data for Detroit A book about demographic changes in Detroit
A McDonald's commerical A documentary about McDonald's advertising
The results of an experiment or clinical trial An overview of different treatments options
An interview with a World War II veteran A history book about World War II

Primary vs. Secondary