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MAS 332: Marine Science II: Primary, Secondary & Tertiary Sources

This guide was created to support Dr. Miller's MAS 332 course

Primary vs. Secondary vs. Tertiary Sources

Primary Sources Secondary Sources Tertiary Sources
  • Information in its original form when it first appears
  • Information has not been published anywhere else, or put into a context, interpreted, filtered, condensed, or evaluated by anyone else.
  • Information that analyzes one or more primary sources
  • May be written in response to a primary article
  • Does NOT contain original research
  • Not written by the people who did the original research
  • Information that restates, rearranges or interprets information from one or more primary sources.
  • Information is organized, indexed, summarized, or compiled from other sources
  • The source will list, summarize, or repackage ideas or information
  • Often not credited to a particular author


  • eyewitness accounts
  • original research (the first publication of a scientific study)
  • letters between two people
  • a diary
  • historical documents such as the US Constitution


  • newspaper or magazine articles that draw upon multiple eyewitness accounts or previous news coverage of an event
  • articles reporting on a scientific study published elsewhere
  • a review of a book


  • encyclopedias
  • Wikipedia
  • directories
  • manuals
  • indexing and abstracting sources

Remember that for many primary documents, such as Euclid's and Archimedes' writings or the letters from Thomas Jefferson to John Adams, we are not going to have the original documents. However, we may have reprints, or the documents may be included in an anthology.

Identifying Primary & Secondary Sources

Indentifying Primary & Secondary Sources