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Historical Research & Historiography

Three Types of Sources: Primary, Secondary, and Tertiary

When conducting research, scholars will consult a range of different sources and documents to gather information, conduct analyses, and provide an interpretation. For the purposes of historical research, these sources can be identified within three categories:

  • Primary
  • Secondary
  • Tertiary

Using a combination of all three types of sources build a more comprehensive and convincing argument. Primary sources are typically used for evidence and analysis, while secondary and tertiary sources are used to show how your research participates in the disciplinary community and the existing body of research on that topic.


Can a source be more than one type?

Yes. The category that a particular source falls into depends on the context with which you are using it. 

For example, a newspaper article could be considered a secondary source for the argument or interpretation of a particular person or event. That same newspaper article could also act as a primary source, though, if you were writing a paper on how media outlets portrayed that particular person or event. 

Primary Sources: the "Raw Materials" of History

Primary Sources are the firsthand evidence of an event or time period. They are produced within that period and can provide insight into how people, institutions, and places lived. Primary sources can take many forms, particularly when conducting historical research. 

Examples of Primary Sources include:

  • personal accounts, like journals, diaries, letters, or memoirs
  • records, such as court transcripts or tax ledgers
  • photographs, audio and video recordings, films
  • published books, novels, short stories, speeches
  • pamphlets, newspaper articles, or magazine articles
  • advertisements or printed ephemera
  • non-textual artifacts, like furniture, curiosities, jewelry, clothing, costumes

Searching for Primary Sources

There are a variety of ways to search for primary sources. When you begin your search, consider these questions:

  • How might people in that time documented or recorded this event, topic, or person?
  • What institutions or organizations were involved in the event, topic, person?
  • What persons were involved in the topic and how might I find their perspective?

Many university, research, and cultural institutions have made great strides in creating digitized versions of primary source material. Below are several repositories to consider as well as tips for searching within the Collier Library's digital resources.

Primary Source Databases for Documents, Books, Diaries, Video

Historical Newspaper Databases

Publicly Available Digitized Collections

Secondary Sources

Secondary sources are pieces of historiography that use primary sources to offer an analysis, interpretation, or a synopsis as well as other secondary sources to inform that perspective and context.

Secondary sources are not simply chronologies of historical events nor are they impartial  - they are books, articles, and more that provide a specific argument or interpretation about the past that is rooted in the historical evidence they use, i.e. primary sources. Historians will include other secondary sources in order to substantiate claims they make, to challenge other interpretations, or to supplement perspectives from other historians.

Examples of secondary sources :

  • Monographs
  • Scholarly Books
  • Essays in anthologies
  • Articles from edited collections
  • Articles from Scholarly Journals
  • Biographies
  • Book reviews
  • Documentary films
  • Literary criticism


Searching for Secondary Sources

When searching for secondary sources, you may wish to consider a range of sources including scholarly articles, books, monographs, biographies, and more. Once you have identified your topic and created your search strategy, use the limiters within a database to narrow down by these source types. 

Databases for Secondary Sources

Tertiary Sources

Tertiary sources often include both primary and secondary sources, but they do not present any new information or analysis. They typically accumulate a number of separate but related accounts of a particular event, issue, or body of scholarship. They are good starting points to a new topic or project, because they can quickly distill a vast amount of information and provide links to more specific or detailed secondary sources.

Examples of tertiary sources:

  • Reference works
  • Encyclopedias or Encyclopedic Databases
  • Dictionaries
  • Textbooks


Searching for Tertiary Sources

When searching for tertiary sources, consider what type of reference you are hoping to find. Are you interested in clarifying the definition of a historical term? You may need a dictionary. Are you wishing to find a quick review of a major event in history? You may need an encyclopedia article or textbook discussing the event. Include these source types as keywords to narrow in on these resources.