Lesson Study: does it affect activating behaviors of mathematics teachers?

This study explores the effects of Lesson Study on activating teaching strategies of mathematics teachers in the context of an interschool Professional Learning Community in The Netherlands. In Lesson Study research, effects are mostly reported based on selfreporting. In a case study of three advanced beginners (3 – 6 years of teaching experience), we explored the effectiveness of Lesson Study by using a mixed-method of observations and teacher self-reports by means of interviews and questionnaires. Results indicate that two of three teachers report effects on their teaching. For one of those two teachers the self-reported effects were also observed. The third teacher does not report effects, nor were effects observed. Lesson Study seems to affect activating teaching strategies of mathematics teachers, but not in all cases