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Biology: Primary and Secondary Sources

This guide shows online and print resources related to biology.

Primary and Secondary Sources

What are Primary and Secondary Sources?

Scientific literature is divided into two basic categories - "primary" and "secondary".

A Primary Source is a document or physical object which was written or created during the time under study and is the result of original scientific research or observation. Some types of primary sources include:

  • Scholarly Journal Articles: An article reporting new and original research or findings written by the original researcher.
  • Original Documents: Diaries, speeches, manuscripts, letters, interviews, news film footage, autobiographies, official records
  • Creative Works: Poetry, drama, novels, music, art
  • Relics or Artifacts: Pottery, furniture, clothing, buildings

A Secondary Source interprets and analyzes primary sources. These sources are one or more steps removed from the event.Secondary Sources may have pictures, quotes or graphics of primary sources in them. Some types of secondary sources include:

  • Textbooks
  • Magazine/Journal Articles: Articles which interpret or review previous findings, or which present findings in way more accessible to the general public. They are not written by the original researcher. Examples would be Scientific American or Psychology Today. A "review article" may appear in a scholarly academic journal, but would be considered a secondary source.
  • Histories
  • Criticisms
  • Encyclopedias

Scholarly Communication Librarian & Science Research Librarian

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Jeff Bond
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Library 2015, right next to Research Support Desk


The information on this page is reused with permission from a Research Guide written by the Loyola University Chicago Reference Department.