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What is the difference between correlation and causality?

by 케미1004 2024. 1. 11.

 

Let me explain the difference between correlation and causality.

 

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Correlation and causality are concepts in statistics and research [that describe different relationships between variables].

Correlation:

 

Correlation refers to a statistical measure [that quantifies the extent to which two variables change together]. In other words, it measures the degree of association between two variables.

A correlation can be positive, negative, or zero. A positive correlation means that as one variable increases, the other variable also tends to increase. A negative correlation indicates that as one variable increases, the other tends to decrease. A correlation of zero suggests no linear relationship between the variables.

However, correlation does not imply causation. Just because two variables are correlated does not mean that one causes the other. Correlation only measures the strength and direction of the relationship.

 

 

 

Causality:

Causality, on the other hand, refers to a cause-and-effect relationship between two variables. In a causal relationship, changes in one variable directly result in changes in another.

Establishing causality is more complex than identifying correlation. To claim causality, researchers often rely on experimental designs, where they manipulate one variable (independent variable) and observe the effects on another variable (dependent variable). Randomized controlled trials are a common experimental design for establishing causation.

Establishing causality requires demonstrating not only a statistical relationship but also a logical and temporal connection, ruling out alternative explanations, and considering the possibility of reverse causation or third-variable confounding.

 

 

 

In summary,

correlation is a statistical measure of the degree of association between two variables, while causality refers to the cause-and-effect relationship between them. Correlation does not imply causation, and establishing causality requires more rigorous evidence and study design.