Correlation coefficients are generally considered strong if they are at least ______.

• A. 0.4 or -0.4
• B. 0.6 or -0.6
• C. 0.8 or -0.8
• D. 0.2 or -0.2

Answer: (B)

Correlation strength is about how tightly two variables move together. The correlation coefficient runs from -1 to 1, and the larger the absolute value, the stronger the linear relationship, regardless of direction (sign).

A commonly used rule of thumb is that an absolute value around 0.6 or higher indicates a strong relationship. So 0.6 or -0.6 best fits the idea of a strong correlation. Values like 0.4/-0.4 are typically viewed as moderate, 0.2/-0.2 as weak, and 0.8/-0.8 would be very strong—beyond the typical threshold for “strong.”