A health psychologist is doing an experiment testing the effectiveness of four techniques for helping a person to relax. The psy
chologist has a limited number of people available to participate in the experiment and each relaxation technique takes some time to complete. The psychologist has decided, therefore, to use the incomplete repeated measures design with all possible orders to balance practice effects? How many participants will the psychologist need at a minimum? A. 4
B. 12
C. 24
D. 48
24 participants will be needed by psychologists at a minimum, to perform his experiments.
This is basically a statistical question in which the possible outcomes of the minimum number of people needed for the experiment is required.
So such questions can be solved by a simple method in which we take the number of techniques and multiply them with their descending number till 1. For example in this question, the number of techniques are 4. so it would be 4! which means we can take out the minimum number of participants by 4*3*2*1, which equals 24. So 24 is the answer.
