Peer Evaluation of Video Lab Reports in an Introductory Physics MOOC

Assessing student performance becomes challenging when course enrollment becomes very large (~10^4 students). As part of a Massive Open Online Course (MOOC) in introductory physics offered by Georgia Tech in 2013, students submitted video reports on mechanics labs. Peer evaluation of these reports provided the primary method for evaluating student laboratory work. This paper describes the methods developed and used to guide students in evaluating each other's video lab reports. We also discuss how students' peer evaluation behavior changed with different interventions provided in the course.