The impact of Lesson Study on the mathematical achievement of students with moderate intellectual disabilities

Students with moderate intellectual disabilities (MoID students) have great difficulties to learn mathematical concepts. Teachers often try different ways to maximize students’ learning but mostly put too much attention to select teaching strategies based on task analysis without identifying the focus of the topic’s main concepts and the gap of students’ prior understanding in relation to the lesson content. Lesson Study as an approach of teacher professional development has been reported to have direct impact on teachers’ instruction in classroom (Lo, Pong & Chik, 2005). This study aims to investigate the impact of Lesson Study on the mathematical achievement of MoID students by guiding teachers to re-think about their teaching strategies in an identified teaching topic in Mathematics. Three special schools with 6 teachers of mathematics and 27 MoID students participated in this study. The whole lesson study consisted of four teaching cycles and teachers worked collectively to define the foci of the lesson and sketch out the lesson plan. Four of the participated teachers took turn to teach the research lesson in cycles with one teacher teach while the rest observed. The lesson design was evaluated and refined for the next cycle. On the side of students, pre- and post-tests were conducted to them before and after the research lesson. Results of the post-test revealed that MoID students were capable of learning mathematical concepts with remarkable improvement if teacher could direct their attention to address their learning needs. Furthermore, significant student improvement was found in latter lesson cycles. This became a strong evidence for Lesson Study as an effective approach for teachers to accomplish professional enhancement and as a way to improve their teaching practice leading to successful learning for MoID students.