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Information Literacy: 13. Primary & Secondary Sources

Strategies used to incorporate research skills for the College of Arts and Sciences, the Graduate School of Management, the Pacific Northwest College of Arts, and the School of Computing and Informations Sciences.

Primary Sources Video


Primary & Secondary Sources
Learn to distinguish between primary and secondary sources and when to use them in your research.

(SCRIBBR video, 4:12 min.)

Comparing Primary and Secondary Sources

Examples of Primary, Secondary, and Tertiary Sources

Primary, Secondary, and Tertiary Literature

Sources of information are often considered primary, secondary, or tertiary depending on their originality and their proximity to when the information was created.  Consider if it is an original work, or whether it evaluates or comments on the works of others.  Also consider the proximity, or how close the information is to a first-hand account or if it is after the fact. 

It can be difficult to distinguish between the three types of sources.  They even differ between subjects and disciplines, particularly between the sciences and humanities. By understanding the unique characteristics and features of each, you will be able to identify them and maximize their potential use, and ultimately help you become a more effective researcher and communicate your work to others.

Primary Sources Defined

Primary Sources:

  • Are first-hand accounts or individual representations and creative works.
  • Are created by those who have directly witnessed what they are describing
  • Bring us as close to the original event or thought as possible without being filtered, influenced or analyzed through interpretation. 
  • Tend to be original documents that do not usually describe or analyze work by others.
  • May be published or unpublished works. 

Use Primary Sources:

  • When you want to make claims or criticisms.
  • As evidence for theories.
  • To gain timely perspectives on a topic.


  • General Examples: Letters, diaries, speeches, interviews, correspondence, court cases, newspaper articles about current events.
  • History:  Transcript of speech given by Queen Elizabeth I; newsreel footage of World War II.
  • Literature: Fiction such as Miguel de Cervantes' novel, Don Quixote; Shirley Jackson's short story, The Lottery, or poetry by Robert Frost. 
  • Art: Works by artists such as Pablo Picasso's painting, Three Musicians; or Michelangelo's sculpture, David.
  • Social Sciences: Interview transcripts of mentally ill patients; raw, unanalyzed population data; newspaper articles about events. 
  • Natural Sciences: Analyzed results from biological study; analyzed field data collected by environmental org; original experiments or research.

Secondary Sources Defined

Secondary Sources:

  • Offer extensive and in-depth analyses of primary sources.
  • Summarize, evaluate, and analytically interpret primary material, often by offering a personal perspective.
  • Are not evidence, but are useful sources of  different experts' views of the primary sources.
  • Are one step removed from the original or primary source. 
  • Are published works, that list their sources of information which can be then used to locate additional information for your research.

Use Secondary Sources:

  • When you need a summary of primary source.
  • When you need an analysis or evaluation of primary source.
  • To help place first hand experiences into a broader context.


  • General Examples: Textbooks, monographs (scholarly books on a single topic), encyclopedias, analyses, review articles, dissertations, theses,
  • History:  Article analyzing Queen Elizabeth I's speech; book recounting battle history of World War II; biographies.
  • Literature: Literary critiques such as an article that examines Cervantes' writing style; paper discussing motifs in The Lottery.
  • Art: Lecture given about Michelangelo's techniques; criticism or a review of Picasso's painting.
  • Social Sciences: News commentaries; an article analyzing results of mental illness study; a book that discusses population trends over time; evaluations of social and government policy, law and legislation.
  • Natural Sciences: Review articles that evaluates the theories and works of others; article on the environmental impact of pollution

Tertiary Sources Defined

Tertiary Sources:

  • Are distillations and collections of primary and secondary sources.
  • Present a summarized factual representation of information.
  • Are free from biased points of view and critiques.
  • Are the last documents to be published in the information cycle. 
  • Tend to consist of highly reliable and accurate information,
  • Contain broad perspectives of topics. 
  • Offer a general overview of your topic and background information for your research.  


Encyclopedias, dictionaries, handbooks, guides, directories, classification systems, chronologies, and other factbooks.

Willamette University

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