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Identify and Evaluate Sources

101 help to identify types of sources and evaluate them


Primary sources

  • document or record with firsthand information or original data, contemporary accounts of an event, written by someone who experienced or witnessed
  • the event in question created at the time of an event, or very soon after
  • manuscripts, periodicals, scholarly articles reporting original research thoughts, conference proceedings, speeches or narratives, diaries, memoirs, letters, photographs, drawings, sheet music, songs, interviews, government documents, patents, eyewitness accounts ets.

Secondary sources

  • published or unpublished work or document describing, summarizing, analyzing, evaluating, derived from, or based on primary source materials
  • reviews, analysis, reference materials (dictionaries, encyclopedias), textbooks, 

Tertiary sources

  • aim to organize, index or abstract information rather than original research
  • indexes, databases, bibliography, reference materials (dictionaries, encyclopedias), guidebooks, manuals, handbooks, and textbooks, abstracting sources.

Determining what is a primary source can be tricky and depends on the topic, subject, and discipline you are researching. If you are unsure talk to your instructor or librarian.

Adapted from ODLIS


Primary Secondary Tertiary
Statistical table of salaries Article describing trends in salaries Index or database for finding statistics
Clinical trials or results of laboratory experience Systematic literature review Data repository 
The Declaration of Independence Book exploring history and political thought behind Declaration of Independence Almanac explaining documents, symbols, and anthems of the United States
Speech by well-known business leader Biography of business leader Textbook on human resources management
Physical evidence in a court trial Lawyer’s closing remarks/argument Dictionary of criminal justice
Results of a treatment trial testing a new antidepressant on elderly men Book about treating depression with changes in diet and exercise Manual with practical tips for working with elderly patients with depression
Blockbuster movie filmed in 1988 Biography of the lead actor Guide about the movie
Original artwork, perhaps a sculpture Critique of that sculpture Repository of Museum
Notes taken by clinical psychologist Magazine article about the psychological condition Textbook on clinical psychology

Retrieved from

Where to search?

Libraries, archives, museums, agencies maintain archival collections, microfilmed materials, data listed online or published in special repositories.

To search use term AND the types of sources (diaries, interviews, statistics..)

Not all material can be accessible in full text in open access but available with licensed subscription.

To Sum Up

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