Regression toward the mean can occur when:
A) participants who score low on the pretest score higher on the posttest.
B) participants who score high on the pretest score higher on the posttest.
C) participants in the control group score higher than those in the treatment group.
D) participants in the treatment group score higher than those in the control group.

Question

Quizplus · Accepted Answer

Regression toward the mean refers to the phenomenon where extreme scores on one measurement tend to be closer to the average on a subsequent measurement. This can happen due to random error or fluctuations in performance. Choice A describes this phenomenon, where participants with low initial scores improve (move toward the mean) on a later test. Choices B, C, and D do not specifically describe regression toward the mean.

Regression Toward the Mean Can Occur When