Concordia.ca / Library / Research skills tutorial / Citing / What to cite

What needs to be cited?

You should provide a reference or citation whenever you introduce a new concept, explanation, fact, or statistic from another source. By doing so, you give credit to the original source and provide evidence that you have carried out your own research. If you are not certain about a particular source, be sure to ask your professor.

You do not have to cite facts, events, dates and concepts that are considered to be common knowledge.

Tip: Determining what is common knowledge

Common knowledge can vary across cultures, academic disciplines, or peer groups. Since common knowledge in one subject area may not be considered common knowledge in another, it is important to consider these questions when deciding if something should be cited:

Who is the audience?
What assumptions can be made as to what prior knowledge they have?
Could you be asked to provide the source of the information you have used?

If you have doubts about what may or may not be considered common knowledge in your discipline, be sure to speak with your professor.

Adapted from Academic Integrity at MIT, "What is Common Knowledge?" and Yale Centre for Teaching and Learning, "Common Knowledge."

Example: Common knowledge

Remember that common knowledge in one subject area may not be considered common knowledge in another. When in doubt, the safest thing to do is to cite your source.

Common knowledge (probably don't need to cite in your discipline)	Specific knowledge (always need to cite, no matter what discipline)
King Henry VIII of England had six wives.	Jane Seymour, the 3rd wife of Henry VIII, was also his 5th cousin (Beer 2004). Beer, Barrett L. 2004. "Jane [née Jane Seymour]." In Oxford Dictionary of National Biography, edited by David Cannadine. New York: Oxford University Press. https://lib-ezproxy.concordia.ca/login?url=http://www.oxforddnb.com
Van Gogh was a Dutch painter.	When he was 16, Van Gogh became an apprentice at the Hague branch of Goupil & Co., an art dealer firm where his uncle was a partner. (Uitert 2016) Uitert, Evert van. 2016. "Gogh, Vincent (Willem) van." In Oxford Art Online, edited by Judith Rodenbeck. Oxford: Oxford University Press. https://lib-ezproxy.concordia.ca/login?url=https://www.oxfordartonline.com
The structure of DNA is a double helix.	Mitochondrial DNA abnormalities are the root cause of many disorders, such as the Kearns-Sayre syndrome (Beers 2006, 2700) Beers, Mark H. 2006. The Merck manual of diagnosis and therapy. Rahway: Merck.

Common knowledge
(probably don't need to cite in your discipline)

Specific knowledge
(always need to cite, no matter what discipline)

King Henry VIII of England had six wives.

Jane Seymour, the 3rd wife of Henry VIII, was also his 5th cousin (Beer 2004).

Beer, Barrett L. 2004. "Jane [née Jane Seymour]." In Oxford Dictionary of National Biography, edited by David Cannadine. New York: Oxford University Press. https://lib-ezproxy.concordia.ca/login?url=http://www.oxforddnb.com

Van Gogh was a Dutch painter.

When he was 16, Van Gogh became an apprentice at the Hague branch of Goupil & Co., an art dealer firm where his uncle was a partner. (Uitert 2016)

Uitert, Evert van. 2016. "Gogh, Vincent (Willem) van." In Oxford Art Online, edited by Judith Rodenbeck. Oxford: Oxford University Press. https://lib-ezproxy.concordia.ca/login?url=https://www.oxfordartonline.com

The structure of DNA is a double helix.

Mitochondrial DNA abnormalities are the root cause of many disorders, such as the Kearns-Sayre syndrome (Beers 2006, 2700)

Beers, Mark H. 2006. The Merck manual of diagnosis and therapy. Rahway: Merck.

Updated: September 27, 2023