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HS 1363: Intro to Public Health

Research vs Not Research Evidence vs Not Evidence

Primary? Secondary? Tertiary

Primary Literature

Primary Literature is the original report of an event or an experimental research study that has been published for the 1st time.

The person who performed experimental research (principal investigator) or the person who observed and then described the event personally is the author.  The contents are 1st-person…

          “I did blah blah blah…”       "We did blah, blah, blah..."

Primary research articles provide details and specifics about the research study being documented. It will include descriptions of study elements such as methodology, number of participants, and data obtained through controlled testing. It will discuss and explain the scientific results, and it will document the researcher’s conclusions and put everything into a context. 

HINT: Look at the METHOD section in an article to see the author describe what his research team did when testing an hypothesis.

Not all primary literature is scientific.  Diaries are primary, but not scientific . Editorials are primary, but not scientific. They are 1st person accounts, but not scientific.

Secondary Literature

Secondary Literature is literature that talks about other literature.
Secondary literature discusses or rehashes what somebody else has already written or said or reported.

          “John said he saw blah blah blah…”       "Studies show xyz123 blah blah blah..."

Secondary literature is a compilation, synthesis, summary, or review of previously published primary research.

Secondary literature is second-hand information.

Review articles found in a databases discuss several other research studies. That review article is secondary, and it may or may NOT be reliable.  Why?

  • Studies included in a review article may be old / stale / not current because the cited studies have already gone through their own publication cycle before going through this 2nd review article publication cycle. 
     
  • The author of the review may have cherry picked  the studies to review (chose only the studies that say what the author wants to write about or the studies align with the author's personal observations or biases), and therefore, the review article's findings may be suspect (not reliable).

 

Review articles are NOT rigorous science. None of them. Ever. Use them for background, but never for evidence or decision making.

Tertiary Literature

Tertiary Literature is literature that discusses events or research 2 to 3 years after the original report. 

Tertiary Literature synthesizes and evaluates using hindsight purposely -- to get perspective. The information does not have to be the most current information.

Tertiary Literature is the least reliable source of research information in terms of scientific findings. The information is older and less rigorous.  Its purpose is to place knowledge into a continuum (to observe the evolution - state of the science - as of date of publication) on a topic. For example, a  researcher may want to analyze the evolution of the food pyramid over time.

 

 

Primary |  Secondary |  Tertiary Literature    

Examples:

  • A book explaining the COVID Lockdown is tertiary.
  • Newspaper articles quoting economists and politicians during the COVID Lockdown are secondary.
  • Your own written diary account of your experiences living through the COVID Lockdown is primary.