Students' progression in understanding the matter concept

This study presents our attempt to elicit students' progression in understanding the matter concept. Past work has identified the big ideas about matter students need to understand, the many everyday understandings students hold about these ideas, and levels of understanding through which students progress in developing understanding of the big ideas, or the matter concept as a whole. None of this research, however, has investigated whether the hypothesized big ideas represent distinct ideas and if so, how students' progression in developing understanding of the big ideas compares across them. With our study, we aim to provide a more comprehensive picture about students' progression in understanding matter by investigating students' progression in developing understanding of four big ideas about matter (structure and composition, physical properties and change, chemical reaction, and conservation). Based on a framework developed from a systematic review of the literature that identifies five levels of understanding for each of the four big ideas, an instrument based on Ordered-Multiple-Choice (OMC) items was developed to assess students' level of understanding about each idea. This instrument was administered to N = 1,388 students from grades 6 to 13. Multi-dimensional Rasch analysis was used to analyze the data collected. Our analyses confirm that the four big ideas represent distinct ideas although our examination of students' progression in understanding these ideas suggests that three of them develop in parallel. A detailed comparison of students' progression suggests that the hypothesized levels mark a hierarchical series of levels through which all students progress in the same order although not necessarily at the same pace. Together with the instrument developed which provides an efficient and reliable way to assess students' understanding our work may help to inform future efforts in optimizing instruction about matter and investigating students' trajectories in developing an understanding of the matter concept.