From my understanding, grade curving is used as a means to maintain integrity within the university. That is, the purpose of an academic institution is to push students to their fullest potential. In order to do so, a high bar must be set so that even the most dedicated students have something to strive for. I agree. Courses need to be challenging and grade curving is seen as keeping that bar high. Instead, grade curving undermines the fundamental goals of both students and the institution as a whole.
In my opinion, there are three critical issues with grade curving. First, grade curving is an artificial way of keeping the bar high. There is a difference between what students achieve as a grade, and the amount of knowledge they have learned about the subject. Adjusting letters on a transcript does not adjust the breadth or depth of knowledge students have. Students which the university “release” into the world are not going to somehow become more or less qualified by forcing a certain class average. Grades are only a representation of knowledge, their integrity is dependent on how well they align with actual knowledge levels. If the university wants to keep the bar high, it must adjust the amount of actual knowledge, not the numerical representation. Change the course, not the grades after the final.
Second, grade curving does not account for chance (i.e. random error). It may well be that, in a given class, it just so happens that the majority of students are good students. In this case, all students in the class are deserving of their grades. If we were to plot class averages (with the same material, exams, etc.) onto a curve, it will resemble a natural, bell- shaped distribution. Therefore, statistically, we would expect to have an abnormally high class average ~2% of the time. The is no justice in punishing a class of bright students because they got grouped together due to pure luck.
The third issue I have with grade curving is that of faculty integrity. From my knowledge, instructors are put under some pressure to maintain a certain average (e.g., 68%). This data is taken into consideration when faculty apply for, say, full-professorship. The only time I can see class averages as being indicative of teaching ability is if a professor consistently has very high or very low class averages. After time, if a professor is getting higher and higher class averages, it is suggestive that they are becoming one of two things: lazier or better teachers. The rigorous process of becoming a professor leads me to suggest the latter. If professors are becoming better teachers, you would expect them to use their higher teaching ability to teach more difficult material. In this way, the students become more qualified, and the class average will remain at a competitive level in a natural way. Pushing professors to maintain a strict class average is counter-intuitive to the goals of a university.
When professors go up for promotion, they should be judged on the depth of material they can present to students, not class averages.
If students learn the material and ace the course… celebrate! The university should celebrate the fact that they have, in their hands, a phenomenal cohort that is going to do amazing things. Taking into consideration the previous paragraph, the professor should celebrate too. They did an amazing job teaching, and the grades reflect that. A class that gets an 80% average should get a plaque not a drop in grades.