The role of clinical interview in lesson study: Investigating the possibilities of a new professional development model in elementary mathematics education

Given the success of Japanese mathematics education, and Japanese teachers' use of lesson study, and given the need for U.S. teachers to expand their knowledge of students, pedagogy, and mathematical content, there is a need to develop a new form of intensive lesson study that incorporates elements of the clinical interview, with its attendant focus on student thinking. This new model, named Child Study/Lesson Study (CSLS), examines students' thinking and learning in kindergarten through fourth grade (a vertical approach) and blends lesson study and clinical interviews. The purpose of this study was to analyze the implementation of this model in an elementary school and investigate in what ways CSLS accomplishes the following: (a) Increase teachers' understanding of students through classroom observation and discussion. (b) Provide teachers with additional insight into students' thinking through the use of clinical interviews. (c) Influence the planning and execution of lessons. (d) Produce extensive discussion of student learning and thinking during professional development sessions.;The participants in this study included six teachers, one elementary principal, one elementary supervisor, and the students who participated in the clinical interviews. To evaluate the success of CSLS, the qualitative data included: debriefing session transcripts, a post-study questionnaire, and clinical interview observation forms.;The debriefing session transcripts and clinical observation forms provided data showing that teachers increased their understanding of students' thinking. Furthermore, they gained ideas on how to improve their lesson design. The questionnaire showed that teachers deepened their understanding of how students make sense of fractions and of related misconceptions. The clinical observation forms showed that the teachers learned new things about their students' thinking. In general, the data showed that the clinical interview transforms the practice of lesson study by providing teachers with the opportunity to gain insight into their students' mathematical thinking beyond what they learned from observing students during the lesson observation. This insight guides the planning and discussion of lessons and inspires teachers to introduce clinical interviewing into their classrooms.;Recommendations are offered for districts interested in implementing CSLS, textbook publishers, national policy, and for future research.