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Academic Integrity

Guide to having academic integrity and avoiding plagiarism

What Is Common Knowledge?

Information can be considered "common knowledge" if multiple sources have the same information--and none of those sources have a citation for that information.

  • The reason this kind of information is called "common" knowledge is because a large group of people--a community--shares the same knowledge.
  • Since this knowledge is shared--not owned by specific people or groups--a citation is not necessary.

Most definitions of "common knowledge" as it applies to citation agree on two basic points:

1. Common knowledge is facts that, if asked, many (if not most) adults would know.

  • The freezing point of water is 32 degrees Fahrenheit (0 degrees Celsius).
  • There are 50 states in the United States.

2. Common knowledge is also facts that, although many adults would not know by memory, are easily found in multiple reliable sources and are not disputed or controversial.

  • The distance between the Earth and the moon is 238,900 miles.
  • Martin Luther King, Jr. delivered his "I Have a Dream" speech on August 28, 1963.

However, there are also other categories of information that would be called 'common knowledge' in certain circumstances, and in those circumstances a citation would not be required.  These circumstances generally occur within two types of communities:

1. Community with a shared history, culture, language, etc.

  • In the United States, basic information about Santa Claus would be common knowledge, but that information would not necessarily be known by citizens of other countries.
  • The words to the "Happy Birthday" song would be common knowledge to English speakers but not necessarily to speakers of other languages.

2. Community with shared academic/disciplinary knowledge

  • Psychologists would know the symptoms of a common disorder, such as schizophrenia.
  • Business professionals would know what a SWOT analysis is and how that is useful for doing strategic planning.

So, a student including information about a psychological disorder (or a SWOT analysis) in a paper for an English course would need to cite the source of their information--but that same information would not need a citation in an article in a discipline-specific journal.