Primary, Secondary, and Tertiary Sources in the Health Sciences.

Sources are considered primary, secondary, or tertiary depending on the originality of the information and how close they are to the source of information.

Primary Sources

Primary sources (or primary research) presents the immediate results of original research activities and/or new scientific discoveries..  It often includes hypotheses, experiments, analysis of data collected in the field or laboratory and a conclusion.   Primary sources are original materials/information on which other research is based.

These include:

  • Journals or Periodicals: main type of publication in which scientific research is reported. 
  • Theses: detailed accounts of research conducted for the awarding of higher academic degrees.  In many cases, it will also be later reported in a condensed form as a journal article.
  • Conferences: Papers presented at conferences may or may not be subject to editorial scrutiny. Conference papers may not published at all, published only in abstract form, published in advance of the conference as a preprint, published in book form, or as a special issue of a journal.
  • Reports: individual publications reporting research. They may report internal research within an organization, or research done by an individual or organization under contract to a client. They may be freely available, available only to members of an organization, only available by purchase, or published in a journal article. 
  • Patents: provides research information on new products or processes. Once published, patent information is freely available, but rarely republished in journal articles.

Secondary Sources

Secondary sources are those that discuss the original research of others. Secondary sources list, summarize, compare, analyses, interprets, re-packages, and evaluates primary information and studies so as to draw conclusions on or present current state of knowledge in a discipline or subject. Secondary sources will include a reference list to direct you to the primary research reported in the article.

They include:

  • Review Journals : These generally start with Annual Review of …, Advances in …, Current Opinion in …
  •  Article Reviews : Articles that summarize the current literature on a specific topic.
  •  Textbooks : These can be either specialized to a narrow topic or a more boarder overview.
  •  Data Compilations :  Statistical databases (SEERS), Vital & Health Statistics, etc.
  • Article Indexes/Databases: These can be abstracting or citation (e.g. Biological Abstracts/MEDLINE).

They also include:

  • Reviews, systematic reviews, meta-analysis
  • Newsletters and professional news sources
  • Practice guidelines & standards
  • Clinical care notes
  • Patient education Information
  • Government & legal Information

Tertiary Sources

Tertiary sources consist of primary and secondary source information which has been collected and distilled. They present summaries of or an introduction to the current state of research on a topic, summarize or condense information from primary and secondary sources, or provide a list of primary and secondary sources. These include:

  • Encyclopedias
  • Almanacs
  • Fact books
  • Wikipedia
  • Research Information TimelineResearch Quickstarts/Library Course Pages/Pathfinders



Tutorial: Identifying Primary, Secondary & Tertiary Sources in the Sciences (CSB/SJU Libraries): (2021 September 3): 3:46 min.

Primary and Secondary Literature in the Sciences: An Introduction (Egan Library): (2021 February 4): 4:04 min.


Last Updated: Oct 11, 2022 11:49 AM