Correlation Coefficient
This is a measure of the direction (positive or negative) and extent (range of a correlation coefficient is from -1 to +1) of the relationship between two sets of scores. Scores with a positive correlation coefficient go up and down together (as with smoking and cancer). A negative correlation coefficient indicates that as one score increases, the other score decreases (as in the relationship between self-esteem and depression; as self-esteem increases, the rate of depression decreases).