Definition
The letter 'r' is used to denote the coefficient of correlation, or the slope of the regression line showing the linear relationship between two variables. Also called the Pearson correlation coefficient. It takes values between -1 and +1, with -1 representing a complete negative or inverse association and +1 representing a complete positive or direct association. A value of 0 (zero) indicates no linear association between the two variables.
See Also
Correlation Coefficient
Correlation Analysis