How many participants would be needed for a within-subjects experiment comparing four different treatment conditions with a total of 20 scores in each treatment?
A)20
B)40
C)80
D)cannot answer without more information

Question

Quizplus · Accepted Answer

In a within-subjects design, each participant experiences all treatment conditions. Therefore, if there are 20 scores needed for each of the four treatments, only 20 participants are needed, as each participant provides one score per treatment.

How Many Participants Would Be Needed for a Within-Subjects Experiment