Evaluating Multiple-choice Exams in Large Introductory Physics Courses
Phys. Rev. ST Phys. Educ. Res. 2, 020102
The reliability and validity of professionally written multiple-choice exams have been extensively studied for exams such as the SAT, GRE, and the Force Concept Inventory. Much of the success of these multiple-choice exams is attributed to the careful construction of each question, as well as each response. In this study, the reliability and validity of scores from multiple-choice exams written for and administered in the large introductory physics courses at the University of Illinois, Urbana-Champaign were investigated. The reliability of exam scores over the course of a semester results in approximately a 3% uncertainty in students' total semester exam score. This semester test score uncertainty yields an uncertainty in the students' assigned letter grade that is less than 1/3 of a letter grade. To study the validity of exam scores, a subset of students were ranked independently based on their multiple-choice score, graded explanations, and student interviews. The ranking of these students based on their multiple-choice score was found to be consistent with the ranking assigned by physics instructors based on the students' written explanations (r > 0.94 at the 95% confidence level) and oral interviews (r = 0.94+0.06-0.09).