Skip to Main Content
It looks like you're using Internet Explorer 11 or older. This website works best with modern browsers such as the latest versions of Chrome, Firefox, Safari, and Edge. If you continue with this browser, you may see unexpected results.
Logo Link to Canisius College Homepage Logo Link to Andrew L. Bouwhuis, S.J. Library Homepage Canisius College | myCanisius | Desire2Learn

Evaluating Sources: Primary and secondary sources

An overview of evaluating sources, including strengths of different source types.

Primary, Secondary, Tertiary

Primary Source: a document or physical object written or created during the time under study. They offer an inside view on an event.
   - Original Documents such as a diary, speech, interview, official record, autobiography, newspaper articles from the time period being studied
   - Creative Works such as poetry, novels, music, artwork.
   - Relics or Artifacts such as pottery, furniture, clothes, buildings.

Secondary Source: interprets or analyzes primary sources. These are one or more steps removed from the event. They may have pictures quotes or graphics of primary sources in them.
   - Publications such as textbooks, magazine articles, histories, criticisms, commentaries, encyclopedias.

Tertiary Source: compile and distill primary sources, secondary sources, or both.
    - almanacs, encyclopedias, Wikipedia, index, bibliographies.

(Adapted from



an interview with Theodore Roosevelt a book about Theodore Roosevelt
a short story a literary criticism
an autobiography (written by the person the book is about) a biography (written by someone else about a person)
a speech commentary on a Booker T. Washington speech

Regarding Source Criticism

  • Human sources may be relics (e.g. a fingerprint) or narratives (e.g. a statement or a letter). Relics are more credible sources than narratives.

  • The closer a source is to the event which it describes may give an accurate description of what really happened. This might be true of a scientific research study. However, it might not be true of an autobiography which is a person's accunt and interpretation of their own life.

  • A primary source is often more reliable than a secondary source, which in turn is more reliable than a tertiary source..

  • If a number of independent sources contain the same message, the credibility of the message is strongly increased.

  • If it can be demonstrated that the witness (or source) has no direct interest in creating bias, the credibility of the message is increased.
  • Knowledge of source criticism cannot substitute subject knowledge: the more you know about the subject, the more precisely you can identify what you must still find out.depends on your topic.

  • Source reliability depends on your topic - it's situational. For example, a biased website might be inappropriate for one topic but completely appropriate for another.

(Adapted from from two textbooks on source criticism, Olden-Jørgensen (1998) and Thurén (1997) written by historians and Wikipedia.)

Searching for Primary Sources

Primary sources are sometimes collected and re-published as books. There are a number of these collections in the Library and you can use the catalog to search for them. Try a keyword search using words to describe your subject in combination with a term to describe the source.

Some terms that might work in combination with your subject are: correspondence; diary or diaries; interview or interviews; letters; speeches; personal narrative; memoirs; autobiography; laws; treaties; documents; maps; or papers.