"Common Knowledge"

Whose Idea Is It, Anyway?

One of the more complicated aspects of source citation involves distinguishing between "borrowed ideas" (which must be cited) and "common knowledge" (which generally requires no citation). In learning how to draw this distinction, keep in mind these suggested guidelines.

• Well-known or easily accessible facts (e.g., winner of the last World Series) or commonplace observations (e.g., Einstein's prominence in modern physics) need not be cited.
• Unique ideas, controversial or especially important facts, and novel insights must all be cited, and other items meeting none of those criteria may need to be cited as well.
• These judgments often depend on the context, such as the academic discipline of a particular course or the writer's field of study or profession. For example, what is considered common knowledge for an academic journal may not hold true for an undergraduate composition course. If you need help in making that determination, consult with your instructor.
• As you encounter particular facts or ideas, pay close attention to and note the sources.
• Accurate and detailed notetaking is invaluable for documenting and tracking the origins of any borrowed material.
• When in doubt, always cite the source. If you do not recall the source, omit that material or seek guidance from your instructor.