<![CDATA[This study aimed to analyze the implementation of a cooperative approach in improving students’ critical reasoning skills through the Problem Based Learning (PBL) method in seventh-grade students of SMP St. Antonius Ndona. The study was motivated by the low level of students’ critical reasoning skills, indicated by limited participation, lack of confidence in expressing opinions, and difficulties in analyzing problems. A cooperative approach integrated with PBL was considered relevant because it encourages student interaction, teamwork, and systematic problem-solving skills. This research employed a descriptive mixed-method approach. Data were collected through pre-test and post-test, observation, interviews, and documentation. The study was conducted at SMP St. Antonius Ndona, Ende Regency, East Nusa Tenggara, from March 25–27, 2026. The results showed a significant improvement in students’ critical reasoning skills, indicated by the increase in the average pre-test score from 61.4 to 82.7 in the post-test. Observation results also revealed improvements in students’ questioning skills, argumentation, group collaboration, and ability to conclude discussion results. Interviews with teachers and students showed positive responses toward the learning process because the classroom atmosphere became more active, participatory, and student-centered. Therefore, the implementation of the cooperative approach through the Problem Based Learning method is effective as an innovative learning strategy to improve students’ critical reasoning skills at the junior high school level.]]>
