Identifying Information Sources

Primary vs. Secondary Sources

Primary sources are the original documents of an event or discovery such as results of research, experiments or surveys, interviews, letters, diaries, legal documents, and scientific journal articles.  Primary sources are also records of events as they are first described.

Some examples of primary sources are:

  • diaries and letters
  • academic articles reporting NEW data and findings
  • works of literature (poems, novels, plays, etc.)
  • works of fine art (paintings, sculpture, pottery, music etc.)
  • official records from a government, judicial court, or company
  • maps
  • oral histories
  • speeches
  • autobiographies
  • fictional films and documentaries
  • eyewitness new reports*

*Newspaper articles that report on a recent event can be primary sources, but articles that rehash previous events are not primary sources, unless they add new information to the story.

Secondary sources offer an analysis or a restatement of an event or discovery described in primary sources. They interpret, explain or summarize primary sources. Some secondary sources are used to persuade the reader. Secondary sources may be considered less objective. 

Examples of secondary sources include:

  • dictionaries
  • encyclopedias
  • textbooks
  • articles and editorials that interpret or review research works or other primary sources**

**Many academic articles include short literature reviews to establish a starting place or a jumping off point for their own, original research; these are still considered primary sources. However, articles that only review previously published articles and contain no new research are secondary sources; these articles are called systematic literature reviews and can be good sources of information about the state of research on a certain topic.


Primary research

Secondary research

Grey Literature

Also called

  • primary source
  • original research
  • secondary source
  • desk research
  • literature review
  • gray literature


  • Primary research means the collection of data for the first time or the transformation of raw data into new forms as a precursor of analysis.
  • Original report of research direct from the researchers that did the work.
  • Primary research includes qualitative and quantitative research and can include surveys, focus groups, questionnaires, and interviews.
  • Secondary research does not generate new data. It reuses or revisits the primary research of other research projects.
  • Secondary research accesses primary source research that are in libraries, databases, and archives.
  • Written materials which fall between primary and secondary sources
  • Refers to research that is either unpublished or has been published in non-commercial form.


  • Journal articles reporting original (NEW) research, empirical data, and statistics.
  • Experiments, clinical trials, case studies
  • Government documents
  • Manuscripts
  • Legal documents
  • Letters and correspondence
  • Diaries
  • Census and demographic records
  • Creative works such as poetry, music, drama, fiction, art
  • Journal or magazine articles that interpret or discuss previous research findings.
  • Encyclopedias
  • Textbooks
  • Reviews of books, movies, art, plays
  • Books that discuss or analyze a topic
  • Indexes and abstracts
  • Bibliographies
  • Biographies




  • Government reports
  • White papers
  • Policy statements and issues papers
  • Conference proceedings
  • Theses and dissertations
  • Private sector research reports
  • Geological and geophysical surveys
  • Maps
  • Newsletters and bulletins
  • Fact sheets

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