The evolution of student conceptions of the formation of shadows and images

Abstract

The purpose ofthe study was to "film" the conceptual development of students as they were studying the optics of shadows and mirrors using lesson materials which were developed by the Constructing Physics Understanding (CPU) group of Dr. Fred Goldberg of San Diego State University. The materials were adapted for use in the Philippines. The CPU materials include a learning cycle consisting of elicitation of preconceptions followed by concept development activities and finally an application phase. Development of student conceptions could be followed through worksheets, the individual idea journal, transcribed videotaped small group discussions, and individual interviews. The sample was formed by three students of a class of 31 students. The results show that it is indeed possible to describe conceptual development in detail and this description will be provided in the paper. In spite of having only experience with superficial and memory oriented courses in High School, the students were able to actively carry out the CPU concept construction process. The sequence and type of American constructed lesson activities turned out to fit this Philippine sample. More than two years after the study, students still remembered the correct concepts, their preconceptions and the reasoning that changed them.