A number of different instruments are typically used by instructors to assess an undergraduate student's level of understanding of course subject matter and, ultimately, to assign each student a course grade. While homework assignments, quizzes, term papers, group projects, class participation and oral reports are all commonly used, generally, a major part of a student's course grade is based on classroom performance on exams. Many instructors assume or like to believe that the major, if not the only. determinant of student scores on exams is student knowledge and understanding of the material. However, Marotz and Young (1988) suggest that "exam taking ability" measured, in part, by the amount of time spent taking the exam may also be an important factor that affects student grades.