Direction
A positive r means both variables rise or fall together. A negative r means one rises as the other falls.
Correlation basics
How to Interpret a Correlation Coefficient
The coefficient tells you direction and strength. Positive means the variables move together, negative means they move in opposite directions, and the size of r tells you how tight the line looks.
Strength
The closer |r| is to 1, the tighter the relationship. The closer it is to 0, the weaker the linear pattern.
What it does not say
r does not tell you explained variance or causation. Use R² for explanation and p-value for significance.
Quick rule
Think of r as the arrow and R² as the percentage. r tells you whether the line slopes up or down. R² tells you how much of the variation that line explains.
Next
See how much the correlation explains
Move from r to R² and see explained variance as a percentage.
Next
Check whether it is statistically significant
Use the p-value guide after you understand the coefficient itself.