Theoretical Investigation on Molecular Diffusion and Conceptual Change of Preservice Teachers by Inquiry Experiment

Abstract

The scope of this study is: (1) to review or summarize the theoretical explanations of diffusion; (2) to investigate the preservice teachers' understanding of diffusion utilizing the inquiry experiment of diffusion that was developed in this study. The data was collected through questionnaires given to 41 preservice teachers in 3 universities and interviews with 20 subjects from this population, who conducted the inquiry experiment. During the experiment, the data was collected from the students' reports and 3 small groups' audio/video recordings. To understand preservice teachers' conceptions, reports, audio/video recordings, questionnaires and interviews were analyzed and discussed with co-workers. The results follow: (1) The differences between effusion and diffusion as well as equal-pressure experiment and equal-flux one on diffusion were discussed; (2) Most preservice teachers understood effusion and diffusion connected to Graham's law of diffusion by rote and have misconceptions about the diffusion process; (3) They observed two kinds of diffusion experiments (equal-pressure and equal-flux) by inquiry experiment, but the majority of them failed to find conceptual differences between these experiments. After the inquiry experiment, about 40% of the samples modified their conceptions about diffusion.