Understanding Primary, Secondary, and Tertiary Sources

In the previous chapter, we discussed various sources of information—from personal interviews to audio-visual recordings, Web pages to print materials, and more. Sources can be labeled primary, secondary, or tertiary, depending on their distance from the information they share.

Primary Sources

Primary sources give firsthand information—original and unfiltered. Examples are eyewitness accounts, personal journals, interviews, surveys, experiments, historical documents, and artifacts. These sources have a close, direct connection to their subjects.

Example Project

Possible Primary Sources

Predicting your state’s growth over the next decade

Learning NASA’s space-elevator plans

Analyzing themes in The Great Gatsby


Advantages: Primary sources directly address your topic and often provide information that is unavailable elsewhere. For example, the questions you compose for an interview or a survey will likely target your unique interest in the topic. Similarly, to test a particular hypothesis, you can design your own experiment.

Disadvantages: Some primary sources, such as eyewitness accounts, may be too close to the subject, lacking a critical distance. Others, such as interviews, surveys, and experiments, are time consuming to prepare, administer, and analyze. Finally, unless you have been trained in accepted methodologies, your own primary research in certain fields of study may not be recognized as valid.


Consider This

Whether a source is primary, secondary, or tertiary varies by topic. The letters from a Civil War soldier would be a primary source of information about his experiences. However, topics he might include about matters outside of his direct observation (other battle stories, news reported in the camp, etc.) would be considered either secondary or even tertiary information, depending on the situation.

Your Turn Imagine you are researching how the human brain is both like and unlike a computer. Where would you go for information? List two possible primary sources. Compare your ideas with a classmate’s.


Secondary Sources

Secondary sources are one step removed from the topic. While they can be just as valuable as primary sources, you must remember that secondary information is filtered through someone else’s perspective and may be biased.

Example Project

Possible Secondary Sources

Predicting your state’s growth over the next decade

Learning NASA’s space-elevator plans

Analyzing themes in The Great Gatsby


Advantages: Secondary sources provide a variety of expert perspectives and insights. Also, peer review usually ensures the quality of sources such as scholarly articles. Finally, researching secondary sources is more efficient than planning, conducting, and analyzing certain primary forms of research.

Disadvantages: Because secondary sources are not necessarily focused on your specific topic, you may have to dig to find applicable information. Information may be colored by the researcher’s own bias or faulty approach. Also, secondary sources can become outdated (in some fields more quickly than in others).

Tertiary Sources

Tertiary sources provide thirdhand information by reporting ideas and details from secondary sources. This does not mean that tertiary sources have no value, merely that they include the potential for an additional layer of bias.

Example Project

Possible Tertiary Sources

Predicting your state’s growth over the next decade

  • Report by a lobbying group, citing secondary sources
  • Opinion-page essay in a newspaper
  • A student essay comparing scholarly forecasts

Learning NASA’s space-elevator plans

  • Wikipedia.org article about space elevators
  • Web site of a private citizen who is a space enthusiast

Analyzing themes in The Great Gatsby

  • Summary booklet and study notes for the novel
  • Biography of F. Scott Fitzgerald

Advantages: They offer a quick, easy introduction to your topic. They may point to high-quality primary and secondary sources.

Disadvantages: Because of their distance, they may oversimplify or otherwise distort a topic. By rehashing secondary sources, they may miss new insights into a topic.


Additional Resources

Web site: U.S. Census Bureau Homepage

Web site: U.S. Chamber of Commerce

Web site: NASA Speakers Bureau

Video: Team Lasermotive Qualifies for a Share of the $900,000 NASA Power Beaming Prize, YouTube

Web page: NASA Power Beaming Challenge

Web site: The Space Elevator Challenge, The Spaceward Foundation

Web page: The Great Gatsby, The Big Read

Web page: Nonfiction essays by F. Scott Fitzgerald, PBS, American Masters

PDF: Economic Outlook Forecast, Charleston Metro Chamber of Commerce

Web page: Japanese Construction Company Plans Space Elevator By 2050, POPSCI

Web page: Space Elevator Enthusiasts Push On despite Lengthy Time Frames and Long Odds, Scientific American

Web page: NASA TV

Web page: The Great Gatsby, film adaptations, IMDb

Web page: Critical Materials, The F. Scott Fitzgerald Society

Web page: Space elevator, Wikipedia

Web page: A Brief Life of Fitzgerald, The F. Scott Fitzgerald Society

Web page: Why Isn't Gatsby in the Public Domain? Gizmodo

Web page: Great Gatsby, Copyright, and the Public Domain, Matt Dickenson