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How to Avoid Plagiarism

Information on how to paraphrase, quote, summarize, cite.

Common Knowledge?

Common knowledge, or "what everybody knows", is the only thing that does not need to be cited.

How does one know, however, "what everybody knows"?  

In one field, a fact that is considered "common knowledge" to someone within that field, will not be considered common knowledge to someone outside of the field.

Generally, for a fact to be considered common knowledge, it has to meet two criteria:

  1. It must have been published in at least three independent sources; and
  2. It must be known by a wide variety of people.

Ideally, it should meet a third criteria--that is, the fact may be found in general reference sources--general encyclopedias or almanacs.


With controversial issues, common knowledge is factual and must involve agreement among most people.  "It is NOT common knowledge that drilling will affect caribou migration or feeding habits."  While evidence may exist to support this statement, there is not enough agreement to make it "common knowledge." 

"Common Knowledge".  Cornell University.  Accessed 13 August 2010.