Evaluation of a new teaching-learning sequence on the particulate nature of matter using crystal structures

Although there has been extensive research on students’ understanding of the particulate nature of matter (PNM), there is still a lack of research on contexts that can be used to teach this challenging topic. In a previous design-based research study, the authors developed a teaching-learning sequence (TLS) on the PNM in the context of crystal structures based on 40 student interviews using the method of probing acceptance. Data suggested that salt and snow crystals form an effective context for learning the concept of emergence and therefore gaining a better understanding of the PNM. To test whether the TLS also promotes students’ use of the PNM in a realistic classroom setting, a proof of principle study was conducted. In six eighth-grade classes in Vienna, students’ use of the PNM was assessed with a pretest before they were taught the TLS during four lessons. After the intervention, students were given a post-test. Open-ended questions were coded using evaluative qualitative content analysis so that quantitative analysis could be applied. T-tests comparing the means of students’ scores on both tests show significant improvements in students’ use of the PNM in the post-test. The context of crystal structures seems to be helpful to students, as most of them use the PNM when asked about crystal formation. In addition, in the post-test, students more often accepted the idea of empty space between particles and associated particle motion with temperature. However, when asked about phase changes, most students remained in a continuous conception of matter.