Students' Ability to Calculate Their Final Course Grade May Not Be as Easy as You Think: Insights From Mathematical Cognition

Is there an optimal grading scheme? Do psychology instructors prefer one grading scheme over another? These questions were recently posted on the Society for the Teaching of Psychology Facebook page. After reading the responses, we realized that research in the domain of math cognition might help to shed light on an optimal grading scheme and put some of the posters' comments into context. Posters often mentioned 100-point and 1,000-point grading schemes because of the ease with which students could convert course points to percentages. In this Pedagogical Points to Ponder article, we describe the quick development of whole number understanding in the 0-100 and 0-1,000 range relative to the slow development across the lifespan of rational number understanding. Although people struggle to understand fractions, percentages might serve as an intuitive bridge between familiar whole numbers and less familiar fractions. We encourage readers to ponder the fact that grading schemes are inherently relational and people of all ages, expertise levels, and cultural backgrounds fall prey to a common mathematical misconception in which they think about the components of rational numbers-the numerators and denominators-like independent whole numbers. This misconception, known as the whole number bias, may make any grading scheme challenging for students to comprehend. There are many open empirical questions about the optimal grading scheme that college instructors should adopt. Findings from the domain of math cognition can inform empirical research designs that may lead to improvements in students' comprehension of the course grading scheme and motivation, and may even diminish student requests for end-of-term grade bumps.