Correlation
/ˌkɒrɪˈleɪʃən/
Definitions
A statistical measure that expresses the extent to which two variables are linearly related (meaning they change together at a constant rate). It also generally describes any mutual relationship or connection between two or more things.
/ˌkɒrɪˈleɪʃən/
A mutual relationship or connection between two or more things.
Scientists found a correlation between smoking and lung cancer.
💡 Simply: Imagine you see that the more you study, the better your grades are. Correlation is when you notice that two things seem to go together. If one thing goes up, the other usually goes up too, like studying and grades. If one goes down, so does the other.
👶 For kids: When two things happen together! Like, when you eat a lot of candy, your tummy might hurt. That's a correlation!
More Examples
The study showed a weak correlation between income and happiness.
Understanding correlation is key to data analysis.
There is a negative correlation between time spent sleeping and alertness levels.
How It's Used
"There is a strong positive correlation between exercise and health."
"Researchers are studying the correlation between poverty and crime rates."
Idioms & expressions
correlation coefficient
A numerical measure of the strength of the relationship between two variables.
"The correlation coefficient for the data was calculated to be 0.8, indicating a strong positive correlation."
causation vs. correlation
Distinguishing between a cause-and-effect relationship and a simple association between variables. Causation means one thing causes another, while correlation means they just tend to occur together.
"It's important to understand the difference between causation and correlation when interpreting research findings."
From Late Latin *correlatio*, from *correlatus*, past participle of *correlare* 'to have a mutual relation', from *con-* 'together' + *relatus*, past participle of *referre* 'to relate'.
The term 'correlation' began to appear in statistical contexts in the late 19th century, coinciding with the development of statistical methods.
Memory tip
Think of 'co-relation': things that relate or change together.