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Research Guide: ENGL 491 Alice Through the Looking Glass

This material was created by Michaela Ullman in USC Special Collections.

For Michaela Ullmann's complete online guide, visit Primary Sources: A Guide

Primary, Secondary & Tertiary Sources Defined

Primary sources are materials that provide first hand testimony or direct evidence concerning a topic under investigation. They are created by the individuals who either witnessed or experienced the events or conditions being documented. Generally, primary sources are created at the time when the events or conditions occurred, but can also be created later if based on first hand experiences. Primary sources enable you to get as close as possible to understanding the lived experiences of others and discovering what actually happened during an event or time period. 


  • diaries

  • correspondence

  • photographs and illustrations 

  • maps

  • newspaper articles from the time period 

  • manuscripts 

  • pamphlets 

  • broadsides, posters and other ephemera 

  • autobiographical materials

  • interview or speech transcripts

  • oral histories

  • government documents (laws, bills, proceedings, acts, census records, etc.)

Context is everything: distinguishing between the three types of sources (primary, secondary and tertiary) will vary according to context and situation. For example, if you are analyzing how African American history was depicted in middle school textbooks in the 1980s, then the textbooks would be considered a primary source rather than a tertiary one.

Primary sources vary by discipline: different disciplines define primary sources differently. This is because the artifact considered to be a primary or original source varies by discipline. For instance, in the sciences a primary source is one that describes or presents original research, experiments or discoveries. These are often published as journal articles, which in other disciplines are considered secondary sources.  

Discipline Primary Source
Art creative artifacts: drawings, paintings, sculpture etc.
Music sheet music, recordings
English play, poem or novel
Political Science treaties, congressional record
Sciences report/article documenting an original experiment/study
Film/Television script, video recording, film

 Some of this content adapted from:

Secondary Sources interpret and/or analyze primary and secondary sources. Secondary sources can be a useful way of discovering significant primary sources. 


  • Scholarly journal articles - JSTOR, for example

  • Biographies - American National Biography (database)

  • Literary criticism analyzing a play, poem, novel, or short story - Literature Resource Center

  • Political commentary analyzing an election, politician, or event

  • Documentaries - although these contain primary sources, these primary sources have been selected, framed and interpreted and so documentaries are typically not considered to be primary sources as a whole. However, interviews unique to the documentaries can be considered and utilized as primary sources. In general, it is always a good rule of thumb to track down the original source of evidence referenced in a documentary or any secondary source if you want to use it in your research. 

Tertiary Sources provide overviews of a topic and synthesize information from primary and secondary sources. 


  • ​Textbooks

  • Book reviews

  • Wikipedia

  • Britannica Academia Edition

  • A Companion to 19th Century America

Tertiary sources are extremely useful as you begin to look for primary sources. You can use them to find important dates, people, organizations, locations and sometimes terminology from the time period. Once you have this information then you can begin your search for primary sources.