Announcement of Ph.D. Dissertation Defense Joe Olsen: “A Comparison of Student and Research-Based Evaluations of Explanation Quality in an Introductory Physics Course for Engineers”

Instructional explanations are an ubiquitous component of classroom instruction but are neglected in science education research. This thesis aims to develop a model for the dimensions of instructional explanations based on student-identified criteria for high-quality explanations, determine the level of agreement among students on what constitutes a good explanation, document the researchsupported strategies used in instructional explanations, and compare evaluations of explanations based on research with students’ opinions. Nine instructors wrote 45 explanations in response to physics questions, which were scored based on a research-derived rubric. Students in an introductory physics course were asked to make pairwise comparisons and to rank order the explanations, which were analyzed with the Bradley-Terry model and relative placement algorithm. Students also wrote about the criteria that drove their judgements. A model for the dimensions of explaining practice was derived from students’ writings, and hypotheses for modeling student ratings of explanations are presented. I found that students have a wide range of opinions concerning the qualities of high-quality explanations, but their opinions are generally in line with research on explaining. I also present contradictory results concerning the degree to which students agree on explanation quality, which should be investigated in future research.