Changing Bimodal Grade Distributions – A Missed Opportunity?

Abstract

Bimodal grade distributions indicate a gap in learning, where the highest quartile of students is skilful in the subject matter, but the lowest quartile is not retaining course material that demonstrates a good level of understanding. Students in the lower quartile do not necessarily have the same challenges as remedial students (i.e., those that do not meet the minimum course requirement) and should therefore be directed differently. We suggest that it is important to consider which elements of the course can be modified to reduce or eliminate bimodality. We provide here an approach to detect bimodality, explore the causes, and provide potential solutions that could be applied to any course. Our case study is on a third-year biochemistry course where several semesters showed a bimodal grade distribution. While student composition and timing of the course may have contributed to this result, underlying causes that can be controlled by the instructor include the lack of student engagement and academic motivation. Increasing the opportunities to earn marks and receive feedback, adding online components using social media, implementing seminars, and training teaching assistants to lead seminars can help reduce this problem.