For an experiment that compares two treatment conditions with ten scores in each treatment, which design would require the smallest number of participants?
A) Between participants
B) Within participants
C) Matched subjects
D) All designs would require the same number of participants.

Question

Quizplus · Accepted Answer

In within participants design, each participant goes through both treatment conditions, so only 10 participants are needed for the experiment. In between participants design, 20 participants would be needed (10 in each condition). Matched subjects design involves matching participants on relevant variables before assigning them to conditions, which would require at least 20 participants. Therefore, within participants design would require the smallest number of participants in this scenario.

For an Experiment That Compares Two Treatment Conditions with Ten