Fostering Critical Thinking in EFL Classrooms: A Lesson Study Approach in Indonesian High School

Using the Lesson Study approach, this study attempts to strengthen critical thinking skills in Indonesian high school EFL students. Utilizing a qualitative descriptive methodology, four instructional cycles were implemented with 100 students and four teachers at SMA Negeri 10 Ternate. Data were gathered through assessments of lesson plans and observations of classroom activities, utilizing Fisher's (2011) critical thinking markers. The results indicated a substantial enhancement in students' critical thinking skills, increasing from 37.5% to 92.5% across the cycles. This research introduces originality by illustrating the adaptation of Lesson Study within Indonesian EFL environments, where resource constraints and conventional practices frequently obstruct pedagogical creativity. Collaborative planning, multimedia technologies, and peer reflection were essential in promoting higher-order thinking skills. The research finds that Lesson Study is a successful and scalable method for fostering critical thinking in EFL classrooms, providing insights for future educational reforms in analogous worldwide contexts.