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Introduction to Primary Source Research: Evaluating primary sources

Basic information on doing research using primary sources

Do I need to evaluate a primary source?

Just because something is a primary source doesn’t mean that it doesn’t have bias or that the facts shouldn't be verified. Start by determining the purpose/bias of the author of the document.


Here are some factors to evaluate:

  • Date of creation - How close to the event was the item created? The closer to an event the item was created means that the creator should be less reliant on memory and therefore the item might be more accurate.
  • Author/creator - Was the author an eyewitness to the event or an expert on the topic? Is the author a credible and reliable witness or an expert?
  • Intended audience - Who was the intended recipient? For example, letters sent to a best friend, parent or newspaper could have different tones and perhaps different content as well.


If you are concerned that the author might be biased, you should consult other accounts and compare them. If several eyewitness accounts agree, you can feel confident that the events occurred as described in your original source.


Don't forget to validate/verify the information in the document. What other sources might you consult to verify the information in this item? For example, city directories and phone books can be used to confirm addresses.


Does your source support the information you found in your secondary research? If not, you should try to determine why this is the case.

CORE Picket Line

CORE picket line outside J.C. Penney's, 1963