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Primary Sources – United States and California History: What is a Primary Source?

The purpose of the guide is to help users identify, locate, and use primary sources in their historical research.

Primary, Secondary and Tertiary Sources

What are primary sources?
         Primary sources are materials that contain direct evidence, first-hand testimony, or an eyewitness account written at the time of a specific event or topic under investigation.  They present original thinking, report a discovery, or share new information.  They provide the raw data for your research. 
         Examples include:                                                                                 
         •  Diaries, Letters, Autobiographies, Oral Histories
         •  Speeches, Personal Narratives
         •  Newspaper articles written at the time of an event, Photographs
         •  Original Documents (birth and death certificates, marriage licenses)
         •  Proceedings of Meetings, Conferences, Trial Transcripts
         •  Works of Art, Literature and Music (paintings, sculpture, musical scores, novels, poems)
         •  Artifacts (tools, furniture, clothing, coins)

What are secondary sources?
         Secondary sources are accounts written after the fact.  They are interpretations, discussions or evaluations of primary sources.  Secondary sources are not evidence, but rather commentary on or discussion of evidence.  

         Examples include:
         •  Monographs, other than fiction and autobiography
         •  Magazine and journal articles (depending on the discipline, can be primary)
         •  Biographical Works

What are tertiary sources?
         A Tertiary source is a summary, compillation or collection of primary and or secondary sources.

         Examples include:
         •  Textbooks (can also be a secondary source)
         •  Almanacs, Fact Books, Directories
         •  Dictionaries, Encyclopedias (can also be secondary sources)
         •  Guidebooks, Manuals, Companions


Take a Quiz:  Which of the three books below is a primary source, which book is a secondary source, which book is a tertiary source?
Need help?  Ask a librarian at the Informtion Desk at Foothill Library.


             Cover           Cover           Cover
             The Great Depression:       The Reader's Companion         Dancing in the dark: A 
             A Diary                             to American History                Cultural History of the
                                                                                                 Great Depression

Examples of Primary, Secondary, and Tertiary Sources Across Different Disciplines

Art and Architecture Painting by Manet Article critiquing art piece ArtStor database
Chemistry/Life Sciences Einstein's diary Monograph on Einstein's life Dictionary on Theory of Relativity
Engineering/Physical Sciences Patent NTIS database Manual on using invention
Humanities Letters by Martin Luther King Web site on King's writings Encyclopedia on Civil Rights Movement
Social Sciences Notes taken by clinical psychologist Magazine article about the psychological condition Textbook on clinical psychology
Performing Arts Movie filmed in 1942 Biography of the director Guide to the movie

From University of Maryland Guides for Information Resources

Evaluating Sources

To understand the value and limitations of a primary source, ask the following questions:  

•  Is this source a firsthand account, written by a witness or participant, and what is his or her relationship to the information contained in the source?

•  Was it written at the time of the event or later?

•  Also, compare the accounts of one event provided by different primary sources to evaluate the reliability of each document. When sources conflict, consider possible explanations for the differences. Do not assume that one type of document is necessarily more reliable than another. A published newspaper article, for example, may reflect the biases of a reporter or editor. An impassioned speech may contain factual information.

For addiitonal information see:
"Reading Primary Sources"
(from the Homepage of Brian Casserly, University of Washington)