Primary Sources, Secondary Sources and Tertiary Sources

 

In addition to thinking about the type of source you might use (e.g., a book or a scholarly journal article), information is also classified as being a primary, secondary, or tertiary source.

 

When considering whether a source is a primary, secondary, or tertiary source, look at how close an author or creator of information is to the event portrayed.

 

  • Primary sources are original materials. They are from the time period when the event occurred and provide first-hand testimony or evidence. They present original thinking, report on discoveries, or share new information. Examples: diaries, letters, speeches, works of literature, scientific journal reporting original research, original documents, like a birth certificate or a patent, raw data or statistics, etc.

 

  • Secondary sources interpret, analyze or summarize. They have been created after the fact with the benefit of hindsight. They comment on or discuss the evidence provided by the original work. Examples: biographical works, commentaries, magazine articles, review articles, scholarly books, popular non-fiction, etc.

 

  • Tertiary sources summarize and condense. They aim at organizing known information to put it into a convenient, easy-to-read form. Examples: bibliographies, dictionaries and encyclopedias, directories, etc.

 

Comparison of Information Sources by Discipline

Primary Source Secondary Source Tertiary Source
Art Original painting Review article Encyclopedia of Art
Psychology Notes taken by a clinical psychologist Book giving an overview of the condition Dictionary of Psychology
Engineering Patent Newspaper article McGraw-Hill Dictionary of Engineering
History Slave diary Biography about a slave Encyclopedia of Slavery
Medicine/Health Original research published in journal Magazine article about the findings Handbook of Family Health

 

How can you tell?

The following questions might help you determine how far removed from the original event a source is:

  • How does the author/creator know these details (names, dates, times)? Was the author present at the event or soon on the scene?
  • Is this an original work based on first-hand experience?
  • Where does the information come from – personal experience, eyewitness accounts, or reports written by others?
  • Is this work based on a single piece of evidence or have many sources been taken into account?