Why do some professors grade on a curve?
Why are so many classes at BYU “curved”? It seems like in many classes students aren’t encouraged to help each other or work in groups, but compete and hope for other students to fail the test. I know the “real world” is competitive, but should education be as well? Isn’t the whole (working together as a group) greater than the sum of its parts?
Thank you for the question! The issue of grading and fairness hits home for both instructors and students. Accurately assessing how much students have learned is one of the most challenging aspects of teaching, and assigning a fair grade isn’t any easier. As one of my colleagues pointed out, three purposes for assessments (and for eventually assigning grades) come to mind:
- To discern whether students have achieved course goals for learning;
- To identify content areas where students are performing well or poorly; and
- To improve learning activities and assessment practices within the course.
Instructors use different strategies to accomplish those goals, which is where two main types of assessments come in. We can either compare each student’s performance to a set standard of performance (criterion-referenced assessment), or we can compare students’ performance to that of each other (norm-referenced assessment). The latter option is where the so-called “curve” comes in.
So why would an instructor use a curve to assign course grades, rather than simply compare students’ performance to a defined standard of perfection and let the scores fall where they may? Here are the reasons another colleague cited for using a curve:
- Some faculty who grade on a curve believe that students will be motivated to study if they know that only a limited number of students can receive an “A” grade.
- Some who grade on a curve believe that it is the only way to guard against grade inflation.
- Most who grade on a curve do it because their discipline has a long-established tradition of such a practice.
- Some who grade on a curve do so because they are following a high-stakes testing model such as the ACT or the GRE. These tests are used to determine which students are accepted or rejected by educational institutions. Some faculty believe that the only way to prepare students for such norm-referenced tests is to give such tests in their own courses.
You’ve probably had some experience with curved grading as a means of preparing students for national norm-referenced tests or for selecting students to participate in certain areas of study. The purpose of such curves isn’t primarily to find out what students know, but rather to sort students into categories for decision makers to use when admitting candidates into competitive fields or programs. As one instructor explained,
Classes that grade on strict curves are (in my experience) “weeder” classes. Some majors and professions—especially in scientific and technical areas—sound appealing but they require a very good grounding in math and science. The people who succeed in these weeder courses are both talented and hard workers—those who are willing and able to do what it takes to reach the top. The class is designed to single out those students who have the potential to become the best in their field.
Getting discouraged? Don’t! In some cases, curves actually help students. For example, one instructor noted,
Every time I have curved the grades in a challenging class, the curve has helped the students by bringing up everyone’s score. I think the only time a student would be harmed by a curve is if the course is easy. I can envision a scenario in that case when students’ grades would be forced downward, but I’m not sure this happens very often. But in ten years of teaching, I can honestly say that I have never once decreased a student’s grade by applying a curve. That’s because in every class I’ve taught (~90 classes), students have fallen out along a curve without my trying to make it happen! Such is the magic of the normal distribution.
Another instructor laid out her typical strategy that combines criterion-referenced assessment and slightly curved grading to the students’ advantage:
Some faculty, myself included, usually grade by a fairly objective standard; i.e., 93–100 percent=A, 90–92.9=A-, and so on. However, when calculating final semester grades, I notice that total scores are often distributed in clear cohorts. As a result, I may shift grading standards slightly either upward or downward by a percentage point or some fraction thereof, depending on how many scores appear in a particular “lump” or grouping. The real-world factor thus enters in to an extent, but arguably in a natural, not excessively punitive, way. (In other words, a typical “A” student doesn’t become a “B-” student as a result of this approach.) Incidentally, my courses are heavily team driven, with an emphasis on cooperation and peer review.
Finally, it’s important to remember that you can influence the course of your own education. If you have questions about grading or assessment practices, or if you notice that competition among students is lessening rather than building opportunities for collaboration, you can talk with your instructor about your concerns. Approach him or her in a spirit of respect and sincere inquiry, and find out the rationale behind the assessment/grading scheme. Be ready to listen—and be ready to offer workable alternatives backed up with sound examples and evidence.
Even though it may feel as though instructors and students sometimes are on opposite sides, we really are all in this together—we all want the best possible learning experience. One last contribution from another instructor sums up the situation very well:
Traditions, such as grading on a curve, are changed when many begin to question them and to suggest viable alternatives. Grading rubrics, like any pedagogical practice in a classroom, can be improved by students and faculty working together to find more satisfying and effective ways to increase learning.