A teacher gave his class a brief quiz to assess their knowledge. On the basis of this test, he gave extra tuition to the pupils who finished in the lower 50% of the class. After one month, he gave them another quiz. He found that the pupils who received the extra tuition improved more than the other pupils. Why might the teacher have observed this apparent difference in improvement?
A) Testing effect
B) Crossover effects
C) Differential mortality
D) Regression towards to the mean

Question

Quizplus · Accepted Answer

The teacher may have observed this apparent difference in improvement due to regression towards the mean. The students who performed poorly in the first quiz were likely to have done so due to chance factors rather than their actual abilities. Therefore, when the teacher gave them extra tuition and they took the second quiz, their scores improved towards their actual abilities. Conversely, the students who performed well in the first quiz may have done so due to chance factors and therefore their scores regressed towards their true abilities in the second quiz. This phenomenon is known as regression towards the mean.

A Teacher Gave His Class a Brief Quiz to Assess