Skip to main content
Roosevelt University in Chicago, Schaumburg and Online - Logo

BIOL 366/466

Characteristics and Examples

This chart explains the characteristics that distinguish primary sources, secondary sources, and grey literature. It also includes examples to help you with identification.




Primary Sources (Direct first-hand evidence)

  • Usually found in journal (In required scholarly article format)
  • Reviewed by expert(s)
  • Published and indexed by commercial publishers
  • Reported by researcher(s)
  • Undergoes peer, jury, or referee review process
  • Reports scientific discovery
  • Presents experiment/clinical trial results
  • Factual/not interpretive

Secondary Sources (Summary of scientific research)

  • Usually written in prose
  • Could be found in book, journal, magazine, online, etc.
  • Written in language for the lay person
  • Not reported by researcher(s)
  • Published account of research study
  • Published account of scientific experiment/clinical trial
  • Proceedings from conference/meeting

Grey Literature (Initial reporting of research findings)

  • Not published by commercial publisher
  • Not easily searchable (Probably has not been indexed)
  • Often published later as primary literature (After the review process)
  • Reported by researcher(s)
  • Government document
  • Document from academic institution
  • Report
  • Research paper

What Is a Scholarly and Peer Reviewed Article?