Investigating the effectiveness of LESSON STUDY on Student's Mathematic Academic Achievement

The purpose of this research was investigating the effectiveness use of lesson study (JOGYOU KENKYU) on third graders mathematic achievement in Qom city. Lesson study is a new educational model which used extensively throughout Japan and involved groups of teachers meeting regularly over a period of time for cooperative designing (planning), teaching, observing, evaluating, and revising lessons in actual classrooms. The sample was randomly selected from Qom’ districts (24 classrooms in 8 schools). Experimental group was 12 teachers and 300 students and control group was12 teachers and 325 students. The research design was pretest-posttest with control group. In the beginning, conducted instructional sessions for experimental (5) and control (1) groups, then executed this model in 12 mathematic lessons for 12 weeks, and finally analyzed data by ANCOVA. The results showed significant differences between the mathematic achievement of experimental and control groups.