A researcher is using 48 subjects in a 4 (levels of exercise) X 3 (levels of caffeine) between subjects factorial experiment. The degrees of freedom for the exercise by caffeine interaction is
A) 12 X 48
B) 48
C) 12
D) 6

Question

Quizplus · Accepted Answer

The degrees of freedom for an interaction in a factorial design is calculated by multiplying the degrees of freedom for each factor. For exercise (4 levels), df = 4 - 1 = 3. For caffeine (3 levels), df = 3 - 1 = 2. Therefore, the interaction df = 3 * 2 = 6.

A Researcher Is Using 48 Subjects in a 4 (Levels