To compute a correlation coeffi cient between traits A and B, which of the following must you have? a

To compute a correlation coeffi cient between traits A and B, which of the following must you have?

a. One group of subjects, some of whom possess characteristics of trait A and the remainder of whom possess those of trait B

b. Measures of trait A on one group of subjects and measures of trait B on another group

c. One group of subjects, some who have both traits A and B, some who have neither trait, and some who have one trait but not the other

d. Two groups of subjects, one of which could be classifi ed as A or not A, and the other as B or not B e. Measures of traits A and B on each subject in one group of students