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Identifying Information Sources

What's the difference?

Telling the difference between primary, secondary, and tertiary sources can often be confusing because the difference is more about the content of the source than the published format. The format may be a first indicator of whether or not a source is primary, but evaluating the content will be the ultimate judgement call.

Primary and secondary sources often differ based on the academic discipline.

This page will give you some guidance on deciding whether a source can be considered primary or not. Many of the formats listed on this guide will exist in both physical and digital modes.

To start, the following video from the Australian National University Library gives an excellent explanation of the different contexts in which sources can be considered primary, secondary, or tertiary.

Primary Sources and Research

Primary sources are the original documents of an event or discovery.  Primary sources are also records of events as they are first described. They are often considered the most credible sources of evidence and are complimented by secondary which will analyze and give context to primary sources.

Some examples of primary sources are:

  • diaries and letters
  • academic articles reporting NEW data and findings - these are often peer reviewed and called empirical research
  • works of literature (poems, novels, etc.)
  • works of fine art (paintings, sculpture, pottery, etc.)
  • works of performance art (music, fictional films, plays, musicals, operas, etc.
  • official records from a government, judicial court, or company
  • maps
  • oral histories
  • speeches
  • autobiographies
  • 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.

Where do I find primary sources?

It depends on your discipline, but here are are some places to start.

  • Academic journals are the main place that most researchers will initially publish the results of their research and/or experiments, though some disciplines will favor book length publications.
  • Creative works like novels, films, music, and other works of art can often be found through the library catalog or special databases from that discipline.
  • Historical sources like newspapers, diaries, letters, oral histories, and more can be found through archival collections, like the Genesee Historical Collections Center and the many online archival databases we subscribe to.
  • The library's homepage search box or subject specific database are great places to start searching!

Secondary Sources and Research

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

Examples of secondary sources include:

  • criticism of a work of art, music, or fiction
  • publications that discuss or analyze a topic
  • articles and editorials that interpret or review research works or other primary sources*
  • some nonfiction books written for general public for entertainment purposes rather than scholarship
  • some textbooks

*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 or analyze 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.

Where do I find secondary sources?

It depends on your discipline, but here are are some places to start.

  • Academic journals will often publish review articles or publications that critically analyze .
  • News sources that offer editorials
  • The library's homepage search box or subject specific database are great places to start searching!

Tertiary Sources

Tertiary sources offer a summary or restatement of facts and research from both primary and secondary sources. The main difference between secondary and tertiary sources is that tertiary sources offer no new information and no analysis of the information from primary and secondary sources.

Tertiary sources are often great places to collect background information and to help locate primary and secondary research.

Examples of tertiary sources include:

  • dictionaries
  • encyclopedias
  • bibliographies
  • some textbooks

Where do I find tertiary sources?

The following databases contain reference sources like encyclopedia, dictionaries, and handbooks.

Comparison Chart


Primary research

Secondary research

Gray Literature

Tertiary source

Also called

  • primary source
  • original research
  • secondary source
  • desk research
  • literature review
  • grey literature
  • reports
  • white paper
  • policy
  • reference works


  • 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 comments on and analyzes 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.
  • Sources which summarize but do not provide new information or analyze other sources of information.
  • Tertiary sources revisits or references primary and secondary research.

Examples of common source formats

  • Journal articles reporting original (NEW) research, empirical data, and statistics.
  • Experiments, clinical trials, case studies
  • Government documents
  • Manuscripts
  • Maps
  • Laws and court decisions
  • 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.
  • Reviews of books, movies, art, plays
  • Books that discuss or analyze a topic
  • Biographies
  • Government reports
  • White papers
  • Policy statements and issues papers
  • Conference proceedings
  • Theses and dissertations
  • Private sector research reports
  • Geological and geophysical surveys
  • Technical reports
  • Newsletters and bulletins
  • Encyclopedias
  • Indexes and abstracts
  • Bibliographies
  • Textbooks
  • Fact sheets