Elementary preservice teachers' conceptual understandings of the cause of moon phases

The purpose of this qualitative study was to describe and understand alternative conceptions and instructional strategies that held promise to promote the learning of scientific concepts. This study focused on the conceptual understandings held by 58 elementary preservice teachers about phases of the moon. Data were obtained for Group 1 participants before and after the completion of an inquiry-based physics course. Data were obtained for Group 2 participants one or more semesters after instruction in the course and for Group 3 participants who received no instruction in the course. The physics course targeted for study used the Physics by Inquiry instructional materials by Lillian McDermott (1996) and her associates. The instructional strategies included recording and analyzing moon observations over time and a psychomotor modeling activity. The method of inquiry for this study followed a qualitative design, involving classroom observations,document analysis, and structured interviews. During the interviews, participantswere asked to use three-dimensional models of the sun. Earth, and moon to show while describing their thinking about the cause of moon phases. Inductive data analysis identified patterns and themes in the participants' conceptual understandings of moon phases.Results indicate that without the instruction most elementary preservice teachers were very likely to hold alternative conceptions of the cause of moon phases. Also, participants who had the instruction were much more likely to hold a scientific conceptual understanding shortly after instruction, and many continued to hold a scientific understanding months later. It was concluded that the instruction is effective in promoting desirable conceptual change. Nonetheless, afterinstruction some participants maintained or added fragments of alternative conceptions while showing many attributes of scientific understanding. The Findings provide a basis for suggestions to inform the practice of using psychomotor modeling of moon phases and other suggestions for instruction.