Which statement about Pearson's r is true?

• A. It ranges from -1 to 1, indicating strength and direction of a linear relation.
• B. It ranges from -1 to 1, but does not indicate direction.
• C. It measures the proportion of variance explained.
• D. It is identical to eta-squared.

Answer: (A)

Pearson's r measures the strength and direction of a linear relationship between two variables. Its values range from -1 to 1, where a positive sign means both variables tend to increase together and a negative sign means one tends to increase as the other decreases. The magnitude tells you how strong the linear association is: values closer to -1 or 1 indicate a stronger linear relationship, while values near 0 indicate little to no linear relationship. It does not tell you the proportion of variance explained—that idea is captured by r-squared, not r itself. It’s also not identical to eta-squared, which comes from ANOVA contexts. So the statement that it ranges from -1 to 1 and indicates the strength and direction of a linear relationship is the correct one.