Using the Rasch model to validate stages of understanding the energy concept

In recent years, there have been efforts to bridge science education with developmental psychology to develop theories on students developing understanding of science concepts from elementary to high school and beyond. The present study intends to test one such theory on students developing understanding of the energy concept. The theory states that students develop understanding of the energy concept by going through the following qualitatively distinct stages: (a) energy as activity/work; (b) energy as sources/forms, (c) energy transfer, (d) energy degradation, and (e) energy conservation. Three classes, one each from 4th grade, 8th grade, and high school physics class (grades 10, 11, and 12), completed a performance assessment. Students' performances were scored based on three traits of energy understanding: attention capacity, qualitative relations, and quantitative relations; each of the traits was defined into five hierarchical levels consistent with the five stages of understanding the energy concept. The Many-Facet Rasch Measurement (MFRM) model was used to analyze the effects of rater scoring severity, students' stages of energy understanding (theta), and difficulties of energy understanding traits. Results show that there was a discontinuity among the stages of understanding the energy concept, supporting the theory on students developing the understanding of the energy concept.