A friend of yours who is a high school senior took the SAT i…
A friend of yours who is a high school senior took the SAT in September and scored in the 95th percentile. Not satisfied with his great performance, he decided to retake the SAT when it was offered the following Spring. That time, your friend scored in the 84th percentile. As a research methods student, you told your friend that the lowered score was most likely due to the following threat to internal validity: