You have designed an experiment with three independent variables: mode of presentation (visual, auditory); difficulty level (easy, difficult); and amount of information (minimal, moderate, maximum). How many subjects are needed, if the three independent variables are between factors, with 10 subjects in each condition?
A) 10
B) 60
C) 70
D) 120

Question

Quizplus · Accepted Answer

To calculate the total number of subjects needed, we need to multiply the number of levels of each independent variable. 
Number of levels of mode of presentation = 2 
Number of levels of difficulty level = 2 
Number of levels of amount of information = 3 
Therefore, the total number of subjects needed = 2 x 2 x 3 x 10 = 120. Hence, the best choice is D.

You Have Designed an Experiment with Three Independent Variables: Mode