Lisa's study assessed the effects of an intervention to facilitate the math skills of low-achieving second grade learners. She administered a treatment to the students in the form of structured computer lesson and found that students' skills increased. With which validity threat should Lisa be most concerned?
A) History
B) Statistical regression
C) Instrumentation
D) Mortality

Question

Quizplus · Accepted Answer

Lisa should be most concerned about statistical regression because it refers to the tendency of participants with extreme scores to become closer to the mean on subsequent testing. In this case, it could be that the low-achieving second grade learners were outliers on the pre-test and the treatment just regressed them towards the mean on the post-test, giving the impression that the intervention was effective. Other validity threats could also apply, but statistical regression is the most plausible given the information provided.

Lisa's Study Assessed the Effects of an Intervention to Facilitate