Primary and Secondary Sources in the Sciences

Primary and Secondary Sources in the Sciences

Sources of information are generally categorized as primary, secondary or tertiary depending on how close they are to the original event or information.  The designation between secondary and tertiary sources is very difficult to make and often unimportant.









  • are original materials on which other research is based
  • present information in its original form
  • experimental research results (Often in articles)
  • patents
  • sets of data, such as census
  • Secondary
    and Tertiary
  • describe, interpret, analyze and evaluate primary sources
  • discuss evidence provided by primary sources
  • are one or more steps removed from the event or information they refer to
  • bibliographies/indexes (e.g. Biosis)
  • biographical works
  • dictionaries and encyclopedias
  • data compilations
  • reviews
  • chronologies
  • directories
  • guidebooks, manuals etc
  • textbooks
  • Some comparative examples of primary and secondary/tertiary sources:






    Patent Index


    Journal article reporting original coral research

    Article reviewing recent coral research.


    Report on a clinical trial of a cancer drug, or a case report of a cancer patient.

    A book about cancer.

    The designations of primary, secondary and tertiary differ between disciplines or subjects.  Primary sources in the humanities and social sciences might be defined differently than primary sources in the sciences.

    Adapted from the guide at the JCU library written by Ward Saylor & Helen Hooper
    Last modified: 8/28/2008 1:57 PM by M. Potter

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