Primary vs. Secondary Sources

When doing research it is important to be able to distinguish between primary and secondary sources. Primary sources are original materials on which other research is based. They are usually the first formal appearance of results in physical, print or electronic format. They present original thinking, report a discovery, or share new information that has not been filtered through the interpretation or evaluation of a second party. A secondary source provides an analysis of or commentary about primary sources. They are often attempts to describe, explain or argue for a particular interpretation of the primary sources.

Examples of Primary and Secondary Sources

Primary Secondary
A painting Article critiquing or describing the painting
Personal diary Book quoting the diary
Report about a clinical trial Analysis of a clinical trial
Original research paper Your use of the research paper for a class assignment
Handmade quilt Image of quilt in a book
U.S. Census Statistics Report about changing populations
Technical reports Reviews of technical reports