A researcher plans to conduct a research study comparing two treatment conditions with a total of 20 scores in each treatment. Which of the following designs would require the smallest number of participants?

Question

Quizplus · Accepted Answer

A within-subjects design (also known as a repeated measures design) would require the smallest number of participants because each participant is measured in both treatment conditions, thus reducing the necessary sample size. A between-subjects design would require twice as many participants (40 total) and a mixed design would depend on the specifics of the study design, but would likely require more than 20 participants total.

A Researcher Plans to Conduct a Research Study Comparing Two