Primary, Secondary, and Tertiary Sources

Sources give your research validity.  Without fact-based research, your paper is simply opinion. Good research is based on verified fact.

There are three levels of sources, based on how close they are to the event or topic being studied.

• Primary:
  Information from direct observation of an immediate event, or from empirical study. Your assignment may require some primary sources.
• Secondary:
  Analysis or interpretation of primary information. Most sources are secondary.
• Tertiary:
  Overview of, guide to, or compilation of primary and secondary sources. 

A primary source is firsthand testimony, direct evidence, or an original creation about a topic. 

Generally, it is created near the time of the topic or event.  Research that is well-founded on primary sources can solidify the authority of a thesis.

In STEM fields, it can be difficult to verify what is a primary source. Here are a few ways:

• Look at the structure. Typically, original research contains a set of sections such as Introduction, Review of Literature, Methodology, Results (charts), Conclusions, References. (Think IMRaD.)
• Search for a relevant word. If your assignment requires you to include primary research in the form of an experiment, search for the word “experiment” within the body of the document. If you need to base your work on primary research obtained by a survey, search for “survey”.

For fields in science, technology, engineering, and mathematics, including medicine —

Primary sources tend to be peer-reviewed original research articles, lab data, data sets, experiments, surveys, statistics, conference reports, algorithms, code libraries, and models. Sources for medicine- or healthcare-related fields may also make use of primary and secondary sources as listed in the social sciences.

Secondary sources can be books and articles about a primary research topic, reviews, editorial articles, biographies, newsletters, documentaries, and professional news sources.

For fields in business, finance, political science, psychology, communications studies, education, sociology, and anthropology—

Primary sources include data sets, statistics, non-profit reports, recordings, speeches, government documents, legal documents, documents of record, peer-reviewed original research articles, test results, experiments, model, surveys, case studies, ethnograhies, recordings, oral histories, the evidence of experts (or in the case of journalism, the experts themselves), and case studies.

Secondary sources can be books and articles about primary sources or a social sciences topic, reviews, editorial articles, biographies, case studies, newsletters, documentaries, and professional news sources.

For history and the humanities (arts, writing/literature, journalism, history, language, philosophy, religion)—

Primary sources include letters, autobiographies, manuscripts, speeches, historical and legal documents, interviews, maps, oral histories, diaries, memoirs, tools or other artifacts, recordings of events as they happen, photographs, [feature] films, personal letters, creative writing (especially fiction), original music, poems, plays, and original creative art.

Secondary sources can be biographies, reviews, books and articles about primary sources or a humanities topic, literary criticism, editorial articles, newsletters, documentaries, and professional news sources.

Explore the finer distinctions among primary, secondary, and tertiary sources.  Complete with Australian accent and humor.