Potentials and pitfalls of design-based research on lesson study: A systematic review

Research into the professional development approach lesson study has produced a substantial international knowledge base, yet robust evidence on its effectiveness remains limited. Design-based research offers strong potential to deepen our understanding on how and why lesson study works across different contexts. This study presents the first systematic review examining how design-based research has been implemented in lesson study research and what insights it provides into adapting the approach and evaluating its impact. Following PRISMA guidelines, we analyzed eleven studies and synthesized their findings to highlight the methodological potentials and pitfalls of design-based research in advancing lesson study research and practice. Our findings show that the iterative process of design-based research is well-suited to uncover how lesson study works, yet only six studies reported their cycles rigorously. To realize the methodology's potential, the field needs consistent, transparent reporting and explicit links to theory.