Andy conducts a study to improve reading scores in elementary schools. He obtains a sample of second-graders whose reading level was very much below average. He enrolls these students in a reading program and then measures their reading level six months later. Reading levels were significantly higher after the program than before. Because Andy selected participants on the basis of their extreme scores, he should be concerned about
A) diffusion of treatment.
B) statistical regression.
C) temporal generalization.
D) instrumentation.

Question

Quizplus · Accepted Answer

Statistical regression refers to the tendency of extreme scores to move towards the mean over time, which could explain the improvement in reading scores rather than the effectiveness of the program.

Andy Conducts a Study to Improve Reading Scores in Elementary