In the Fall Semester, a Professor Compared a Lecture Approach

Multiple Choice

In the fall semester, a professor compared a lecture approach to teaching statistics (using a sophomore class) with a problem-oriented approach (using a senior class) .Both sections were given the same final exam.The professor repeated the same experiment in the spring semester.This study shows a confounding of

A) test scores with teaching approaches.
B) class levels with test scores.
C) teaching approaches with class level.
D) semester with teaching approaches.