When respondents perform well on pretests and poorly on posttests, or vice versa, merely by chance, so that their results cancel each other out when scores are averaged, the outcome is called:
A) regression.
B) inter-observational reliability.
C) drift.
D) maturation.

Question

Quizplus · Accepted Answer

This phenomenon is known as regression or regression to the mean. It refers to the statistical concept where if a variable is extreme on its first measurement, it will tend to be closer to the average on its second measurement, and if it is extreme on its second measurement, it will tend to have been closer to the average on its first. This can lead to misleading conclusions in studies if not properly accounted for, especially in pretest-posttest designs.

When Respondents Perform Well on Pretests and Poorly on Posttests