On the workload and distribution of grades in the Keller individualized teaching

Abstract

Courses based on the Keller method (also named Personalized System of Instruction -PSI) present several interesting features and results, such as final grade distributions which are upside down (the majority of students achieving the highest grades) and a workload for the elaboration and implementation considerably greater than that involved in traditional courses. In the present paper, we propose a mathematical model to describe the scheme of a course implemented according to the Keller plan. This model predicts the time evolution of the distribution of students per unit of content, predicts the upside down effect in the final grades and establishes conditions under which this effect can be observed. The model also provides a quantification of the workload spent in implementing assessments, so it can be an useful tool for those planning or interested in further investigations on Keller courses.