Primary and Secondary Sources

Primary Sources


Primary sources are original materials on which research is based. They are firsthand testimony or direct evidence concerning a topic under consideration. They present information in its original form, neither interpreted nor condensed nor evaluated by other writers.

Whether a source if primary can be determined by the way it is being used by the researcher. For example, a speech about the Declaration of Independence that was delivered by a noted statesman on its hundredth anniversary would be secondary source for a scholar studying the document’s philosophical origins. But it would be a primary source for a scholar studying how the Declaration’s meaning has changed for Americans over time.


  • Newspaper articles (reporting events)
  • Photographs
  • Interviews (legal proceedings, personal, telephone, e-mail)
  • Correspondence
  • Trial transcripts
  • Fiction, poems, music
  • Experimental results
  • Autobiographies, personal narratives, memoirs
  • Diaries
  • Manuscripts
  • Data

Secondary Sources

Kennedy Nixon 1960

Secondary sources offer interpretation or analysis based on primary sources. They may explain primary sources and often uses them to support a specific thesis or argument or to persuade the reader to accept a certain point of view. Such works are one or more steps removed from the event—being written with the benefit of hindsight.


  • Monographs
  • Journal articles
  • Biography
  • Encyclopedias
  • Dissertations
  • Research analysis
  • Works of criticism and interpretation
  • Newspaper articles (analyzing news)

Differentiating between primary and secondary sources

  • Time of publication. Material written close to the time of the event is often primary material. For instance, a diary written a women traveling on the Oregon Trail is primary material as is an article in the newspaper at the time of her arrival in Portland. However, a contemporary article about the hardships of the trip along the Trail would be secondary material.
  • Purpose of the material. An article, book, essay, etc. written with an analytical or persuasive point of view is secondary. The latest population data for New York Counties are primary material; an article describing trends and analyzing the data is secondary.
  • Context of the researching scholar. Primary materials for a critic studying the literature of Desert Storm, the first Iraq War, differ significantly from primary materials for a physician studying the health problems of the soldiers in that war. The critic’s primary materials are the stories, poems, songs of the era. The physician would study the soldiers’ medical records.
  • Primary and secondary sources are not fixed categories. The use of evidence as primary or secondary is determined by the type of research you are conducting.

Definitions for primary and secondary resources vary from discipline to discipline, check with your professor for help specific to your assignment or discipline.

Some comparative examples of primary and secondary sources:

Discipline Primary Secondary
Art Original artwork Article critiquing the work
Engineering Experimental data Journal article analyzing data
History World War II personal narrative Book analyzing military strategies of the War
Literature Shakespeare’s Hamlet Critique and analysis of characters in Hamlet
Science Data reporting oceans’ temperature Analysis of oceans’ changes over the past 20 years
Theatre DVD of a performance Review of the performance
Psychology Notes about a client with autism Monograph on autism