In our country, ‘in-school teacher training’ have been planned and conducted for the purpose of ‘the formation of teaching competence for the teachers’ in each school, where lesson study, as a method of research, is carried out traditionally centered on some classes open to other teachers. It was also shown in “The Teaching Gap (Stigler & Hiebert 1999)” that lesson study has improved the quality of Japanese mathematics teaching, and then Japanese traditional lesson study is now spreading internationally. However, the concrete effects and their factors on the formation of mathematics teachers’ competence for teaching through lesson study have not been yet clarified enough.
In this paper, we focused on the qualitative change of the teacher K’s ways of teaching which occurred while we conducted the ‘School Support Project’ with lesson study. The project was done in a seventh grade classroom with the class teacher K for improving mathematics classes over a four-month period from September to December, 2012. We took two typical teaching episodes in oder to compare the qualitative differences before and after the project. We analyzed them in detail by using mainly two theoretical perspectives: “the Types of MATOME” and “the Didactical Situation Model”.
The analysis of the two episodes revealed the qualitative changes of the teacher K’s ‘ways of teaching’, which are characterized as follows:
･ In some teaching situations, the subject of control in the class interaction changed from the teacher to the students at all levels except the goal level.
･ Not only the type Ⅲ-a of MATOME but also the type Ⅲ-b of MATOME, Student-Guided MATOME, came to be observed.
We clarified some important elements causing these changes. Among these elements, the teacher K’s shift in her listening way seems to be closely related with her new experience, in which she watched her students’ learning processes carefully as an observer several times when the other member of the project team taught mathematics in different ways in her classroom. This fact suggests the necessity of long-term cooperation with others in Japanese traditional lesson study.
