In order to compute a correlation coefficient between traits A and B, it is necessary to have:
A) one group of subjects, some of whom possess characteristics of trait A, the remainder possessing those of trait B.
B) measures of trait A on one group of subjects and of trait B on another.
C) one group of subjects, some of whom have both A and B, some have neither, and some have one but not the other.
D) two groups of subjects, one which could be classified as A or not A, the other as B or not B.
E) measure of traits A and B on each subject in one group.

Question

Quizplus · Accepted Answer

To compute a correlation coefficient between traits A and B, we need to have measures of both traits on each subject in one group. Option E is the only choice that fulfills this requirement. Option A suggests a between-subject design, which is not appropriate for computing a correlation coefficient. Option B also suggests a between-subject design, but with different groups for both traits. Option C suggests a three-group design, which is also unnecessary. Option D suggests a dichotomous classification of each group, which would not allow for a continuous correlation coefficient to be computed.

In Order to Compute a Correlation Coefficient Between Traits a and B