A Case for Stricter Grading

At ABC College, excessive grade innation has hindered the administration's eeorts to identify the most talented students and to rank the students in a reasonable way. We construct a method for more accurately evaluating student ability that adjusts a student's grade based on whether the professor assigning the grade tends to be unusually harsh or lenient. Since we have no real data, we construct a model of grade assignment. This model assigns a grade to a student in a particular course based on the student's inherent ability to perform well, the student's speciic aptitude for the course, the diiculty of the course, and the harshness or leniency of the professor's grading. We note that simply ranking the student body by GPA results in a realtively poor ranking, especially when the average grade is as high as an AWe We develop a more sophisticated student ranking method that corrects the student's grades to take into account the harshness or leniency of each of the professor's grades. We assume that we have access to a professor's previous grading history, so that we can judge how harsh or lenient of a grader each professor is. After making this determination, we correct each grade given by that professor to systematically correct for her bias. After correction, the student body has an aggregate GPA of approximately 2.7, corresponding to an uninnated grade of B-. The corrected GPA values do a considerably better job of accurately ranking the students by ability, especially for students in the bottom seven deciles. 1. Introduction The administration at ABC College is concerned about waning academic standards and grade innation. The average grade given out at ABC is now an A-. For purposes of awarding scholarships the college wishes to establish a class ranking that accurately reeects the academic abilities of the students and there is some doubt that raw grade point averages provide the information necessary for comparing students. The dean has suggested that additional data about the courses students have taken, such as the performance of the other students in the class, could be used to make more accurate comparisons between students and establish a better ranking. Our task is to establish a model that realistically reeects the situation at ABC College and determine if we can use the Dean's idea or some other scheme to accurately compare students.