Common knowledge is defined as factual information that you’d expect most people to know. For example, the capital of France is Paris. Or JK Rowling is the author of the Harry Potter books. You don’t need to cite a source when referencing common knowledge in your papers, as everyone knows it so it doesn’t usually need to be evidenced.

Imagine citing a world map to evidence that the capital of France is Paris — it would seem pretty silly and pointless, right? Plus, you’re also at risk of patronizing your reader!

So If I Know It, It’s Common Knowledge?

Not necessarily! We all have lots of information stored in the back of our mind that we’re not entirely sure how it got there. This could include anything from the fact that the Taj Mahal is a landmark in India to the ingredients in a good guacamole. But you knowing something doesn’t automatically mean that it’s common knowledge.

For example:

A big Harry Potter fan might know that the original book was named Harry Potter and the Philosopher’s Stone, with a release date of June 1997 in the UK. However, many readers in the US will know the book as Harry Potter and the Sorcerer’s Stone. And many more will have no idea of its release date in the US, let alone in the UK.

On the flip side, you not knowing something doesn’t necessarily mean that it’s not common knowledge.

For example:

Capital cities are normally taken as common knowledge, despite the fact that most of us would have to look up the capital city of Christmas Island (Flying Fish Cove!) or Luxembourg (Luxembourg!).

Likewise, many people wrongly assume that a certain city is a country’s capital — that Istanbul, and not the less well-known Ankara, is the capital of Turkey, for example. You still would not be expected to cite a source. However, you might wish to provide more clarification i.e. Istanbul (then known as Constantinople) was the capital of the former Ottoman Empire, but Ankara took over as capital city in 1923, when the Republic of Turkey was formed. In which case, you should cite the source of this info.

Know Your Audience

It’s a good idea to consider your intended audience when determining what constitutes common knowledge for the purpose of your paper or essay. For example, if you’re referencing Picasso for art history class, you might assume that certain facts are common knowledge — yet someone who’s never studied art might know nothing at all about the artist and his work.

Lies, Damned Lies, and Statistics

As the above popular quote alludes, statistics are often stated as fact but can actually be deceptive little things. There are many ways in which a statistic can be skewed — it might come from a sponsored study which leads to a bias result, or there could be a false causality or overgeneralization at play — therefore you should always cite a reputable source.

If you’re in doubt as to whether something that you’re referencing in your essay is common knowledge, the safest option is to add a citation. Citation Machine can help you to create and format citations correctly, using the popular MLA formatting, APA format, and Chicago formats, as well as other styles. Simply check with your teacher or tutors to check which style you should be using and Citation Machine will help you cite your work correctly.