2015．第43卷第2期（Vol. 43 No. 2）．pp. 115–144
Teaching the Concepts of Speed Using Task Design and Experiment
This article aims to report a teaching experiment by an in-service teacher, using the principles of learning trajectories (LTs), with tasks regarding the concepts of speed and to examine the performance of students with regard to speed concepts. With the retrospective reflections made by the teacher after the teaching experiment, the instantiated teaching theories produced was discussed. The subjects of this study comprised a class of sixth-grade students at a public elementary school in Central Taiwan and their homeroom teacher. Teacher-student interactions were recorded; qualitative analyses were used to investigate teacher-student dialogue, the problem-solving performance of the students, teacher reflections, and after-class interviews with the students. Results show that: (a) after the LT-based course and teaching experiment, the students performed well in determining and calculating multiplication and division operations, converting distances and time, comparing speeds, and using average speed units. Students in the low-performing group still needed to improve on division with decimals and fractions, the conversion of fractions in simple denominate numbers, the description of relationships between two units, unit conversion, and the presentation of the problem-solving process. (b) The effect of the instantiated teaching model could be obtained after the teaching experiment of teaching students the concepts of speed and problem-solving strategies. Suggestions were then formulated for future teaching reference and research.
Keywords: speed; teaching; professional development; learning trajectories