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BIOA11: Biology of Humans

Types of Sources

Primary Source:

  • Research which reports first-hand on original findings
  • Includes empirical journal articles and some books (monographs)

Secondary Source:

  • Summarizes, analyzes, or reports the work of other researchers (no new research results are presented)
  • Includes literature review articles, systematic reviews, meta-analyses, newspaper articles, some books, etc.

Tertiary Source:

  • Summarizes well-known and well-accepted information on a subject
  • Includes textbooks, encyclopedias, websites, etc.

Grey Literature:

  • Materials not published through traditional means (e.g. scholarly journals)
  • Includes government or organizational reports, lab notebooks, blogs, pre-prints, conference presentations, etc.

Recognizing Primary Sources in the Sciences

Typically, primary/empirical journal articles will have a common structure that includes:

  • Abstract 
  • Introduction 
  • Methods / Materials & Methods
  • Results
  • Discussion
  • Conclusion

Secondary/review articles frequently contain many of the same sections, but frequently will not have a Methods section. If they do, they will discuss how the articles to be reviewed were found and selected.

Look for a Methods section as a quick check to see if an article may be primary. Read this section to see if the researchers are talking about their new/original research.