Wednesday, August 2, 2006
Biennial Conference on Chemical Education, Purdue University (West Lafayette, IN)
Classroom science demonstrations are intended to serve two important purposes: to increase students' interest in the material being covered and to improve students' understanding of the underlying scientific concepts. Student end-of-semester evaluations typically praise demonstrations as one of the most interesting parts of a course, suggesting that demonstrations accomplish the first objective. What about the second? Do demonstrations effectively help students learn the underlying concepts? We examined whether the mode of presentation of demonstrations affects their effectiveness as teaching tools. Two results are noteworthy: first, we find that students who simply observe a demonstration and hear an explanation of it, without activities that engage them actively with the demonstration, show no greater understanding of the demonstrations at the end of the semester than did students who did not see the demonstration at all. Second, students who predict the outcome of the demonstration before seeing it show a much higher rate of understanding of the demonstration than the students who simply observed the demonstration.