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Loyola University Chicago Libraries


Useful links and databases for research in Biology & interdisciplinary course work.

Types of Academic Sources

There are three main types of sources used in academic research:

  • Tertiary
    • Sources that compile and condense information from other sources and give a broad overview of a topic 
    • Examples include encyclopedias and dictionaries 
    • Great place to start your research
    • Once you have a good handle on the basics of your topic, move on to primary and secondary sources
  • Primary
    • ​​​​​​​Academic research is based on primary sources
    • Provide firsthand testimony or direct evidence concerning a topic
    • Created by witnesses or recorders who experiences the events of conditions being documented
    • Examples include personal papers, news footage and articles from the time of the event, speeches, material artifacts and creative works such as photographs, novels, essays, poetry, music and fine art
    • In the Sciences, scholarly articles are primary sources if they are written by the researcher who conducted the experiment or dollected the data. 
    • In the Humanities, scholarly articles are most often secondary sources that analyze, evaluate, interpret or criticize primary sources
  • Secondary
    • ​​​​​​​Sources that analyze, evaluate, interpret or criticize primary sources
    • Examples include scholarly and popular articles, criticisms, histories and commentaries
    • Two types of secondary sources
      • Scholarly
        • Written by experts in their field for other experts in that field
        • Usually longer and use an academic vocabulary 
      • Primary 
        • Not written by experts in the field and are intended to be read by the general population 
        • Usually shorter and use a common vocabulary 
        • Often contain color pictures and ads 


What are Primary and Secondary Literature?

Literature resources can be divided into two basic categories - "primary" and "secondary."

In scientific literature, 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: Articles 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: These are articles which interpret or review previous findings or 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.
  • Histories
  • Criticisms
  • Encyclopedias