Replacing Summative Peer Evaluation with Self-Managed Group: A Lesson in Illusory Superiority

Abstract

Summative peer evaluation has deleterious effects that can be avoided by a process we call self-managed group (SMG). SMG requires students to specify their preferred group sizes and choose between personal performance and group performance as their preferred bases for group credit. SMG also enables students to re-assign themselves, subject to instructor-set conditions. SMG does require a measure of personal performance closely linked to group output. Group credit for the group assignment is based on the product of the group output score and weighted personal performance, itself computed as the preference weighted sum of each student’s personal performance score and the mean personal performance score of the members of the group. A study of SMG used in conjunction with a computer-assisted, internet-based, one-semester game showed that when the game ended, 94.4% of participants who performed below the mean chose, to their own disadvantage, the personal performance basis for group credit. The disadvantageous effects of illusory superiority, as well as the possibility of high performing members rationally sacrificing personal advantage for group benefits are teaching points that instructors who use SMG with their games and exercises may find productive to explore with students.