ABSTRACT
Many students have difficulty learning symbolic and molecular chemical representations. This study investigates how students develop their understanding of chemical representations with the aid of a visualizing tool, eChem, that allows them to build molecular models and view multiple representations simultaneously. Multiple sources of data were collected with the participation of 71 eleventh graders in a high school over a six-week period. The results of the pre- and post-tests show that students' understanding of chemical representations improved substantially (r=13.9, p<.001, effect size= 2.68). The analysis of video recordings reveals that several features in eChem helped students construct models and translate representations. Evidence also shows that high engagement students' discussions involved both visual and conceptual aspects of representations, which in turn may deepened their understandings of representations. Moreover, the findings suggest that models can serve as a vehicle for students to generate mental images, and that different types of 3D models were not used interchangeably for these students.
