Dimensions of Variation in Chemistry Instructors’ Approaches to the Evaluation and Grading of Student Responses

Abstract

Chemistry faculty instructors (FIs) and graduate student instructors (GSIs) regularly engage in the evaluation and grading of student responses in formal formative and summative assessments. In this study, we identified dimensions of variation in these instructors‘ approaches to the evaluation and grading of students’ answers. Using qualitative methods of research, we conducted individual interviews in which participating chemistry FIs and GSIs were asked to evaluate and grade the same set of students’ responses to a typical exam prompt and justify their decisions. Our results indicate that an observed variability in assigned grades emerged from the complex interaction of explicit and implicit decisions made and preferences manifested along various dimensions. Our findings suggest avenues for the professional development of chemistry instructors that can help reduce grading variability.