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.
A tertiary source is a collection of primary and secondary sources.
To learn more about these types of sources, check out the tutorial on Primary, Secondary, and Tertiary Sources
Examples of Primary, Secondary, and Tertiary Sources
Primary |
Secondary |
Tertiary |
The text of The Gettysburg Address |
An analysis of The Gettysburg Address |
A U.S. history textbook |
Census data for Detroit |
A book about demographic changes in Detroit |
A chronology of major events in Detroit |
A McDonald's commerical |
A documentary about McDonald's advertising |
An encyclopedia of major marketing campaigns |
The results of an experiment or clinical trial |
An article citing different treatment options |
An medical dictionary |
An interview with a World War Two veteran |
A documentary featuring interviews with veterans |
An anthology of first hand accounts from World War Two |