SHIFTING STUDENTS’ AWARENESS OF GEOMETRICAL CONCEPTS THROUGH LESSON STUDY

Students’ performance in geometry and hence, their geometric thinking remain a concern for researchers globally. This quasi-experimental research design aims to investigate the effects of Phase-Based Instruction (LS-PBI) using Geometer’s Sketch Pad to reveal Thai students awareness of geometric concepts. Three groups of mixed ability Grade 7 students (aged 12 – 13) were chosen as participants in one of the schools in Yala Province, Thailand. These groups were taught the topic of Properties of 2D and 3D geometric shapes in a cycle of three instructions by three different teachers engaging in Lesson Study method. A twelve-item multiple choices test was administered to students in each group before and after each lesson study session to assess their understanding of geometrical concepts. Findings of the pre-tests and post-tests revealed that LS-PBI using GSP was effective in revealing students’ shifts in awareness of geometrical concepts. \nKeywords: Geometer’s Sketchpad, Geometric Thinking, Geometry, Lesson Study