Question on Lesson Study

I am a teacher in a primary school in Singapore, currently carrying out Lesson Study in our school. I would like to seek your advice on Research Themes.

I gather that to come up with the Research Theme, the team needs to look at the Ideal Profile of Students and the Actual Situation of Students. This, with the School's and Department's Vision and Mision, the team will construct the Research Theme or Research Focus. My question is once this is firmed up, it will form the basis of all future Research Lessons for Lesson Studies, is that right?

Do we need to come up with a different Research Theme for each cycle of Lesson Study or will the Research Theme be the one that all Lesson Studies be based on. For example, my team has discussed and came up with a Research Theme for Mathematics. Will another Research Theme need to be constructed for a different cycle for Mathematics or can we use this Research Theme we have decided on for all Research Lessons for Mathematics.

Ban Har writes: Based on the school's vision, focus of the curriculum and your students' profile, the research theme is constructed. You are on the right track. You will stick with the same reasearch theme for a while until your team feel that there are new areas that need attention.