Promoting Conceptual Understanding of Chemical Representations: Students' Use of a Visualization Tool in the Classroom

This study investigated how students develop their understanding of chemical representations with the aid of a visualizing tool, eChem, that allows them to build molecular models and simultaneously view multiple representations. Multiple sources of data were collected with the participation of high school students (n=71) over a six-week period. The results of the preand post-tests show that students' understandings of chemical representations improved substantially. The analysis of video recordings revealed that several features in eChem helped students construct models and translate representations. Findings suggest that models can serve as a vehicle for students to generate mental images, and that different types of 3-D models were not used interchangeably for these students. (Contains 46 references.) (Author/WRM) Reproductions supplied by EDRS are the best that can be made from the original document. Promoting Conceptual Understanding of Chemical Representations: oo r-Students' Use of a Visualization Tool in the Classroom zr Hsin-kai Wu, Joseph S. Krajcik, Elliot Soloway C:t The University of Michigan, School of Education, 610 E. University, Ann Arbor, MI48109-1259 Tel: 734-647-4226 Email: hkwu @umich.edu, krajcik@umich.edu, soloway@umich.edu Abstract: 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 preand post-tests show that students' understanding of chemical representations improved substantially (t=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 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. 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 preand post-tests show that students' understanding of chemical representations improved substantially (t=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 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.