Pearson Correlation
A statistical measure that quantifies the strength and direction of the linear relationship between two continuous variables.
What is Pearson Correlation?
The Pearson correlation coefficient (r) ranges from -1 to 1. An r of 1 indicates a perfect positive linear relationship, -1 indicates a perfect negative linear relationship, and 0 indicates no linear relationship. It evaluates how much the two variables vary together relative to how much they vary separately.
Why Pearson Correlation Matters
It is the foundational metric for assessing linear associations in data, serving as a building block for regression analysis, factor analysis, and establishing the reliability and validity of measurement scales.
Example
A researcher calculates a Pearson correlation to examine the relationship between hours spent studying per week and final GPA among college students.
Common Mistakes
- Assuming a high correlation implies that one variable causes the other.
- Using Pearson correlation for non-linear relationships, where it may misleadingly show an r near 0 even if a strong non-linear relationship exists.