Lesson study is an activity where teachers together plan, observe, analyze, and improve their learning. Lesson study is a collaborative activity of a group of teachers to: (1) plan the steps of learning, (2) one of them practices the planned learning and the others observe the learning process, (3) evaluate the implemented learning, (4) improve the original planning, (5) practice it again, (6) re-evaluate the implemented learning, and (7) share experiences and findings from the evaluation results with other teachers.

Lesson Study merupakan suatu kegiatan dimana para guru secara bersama-sama merencanakan, mengamati, menganalisis, dan memperbaiki pembelajaran yang dilakukannya.