<![CDATA[The development of technology has changed the demand for various skills, one of which is critical thinking. However, students’ critical thinking skills remain relatively low. This study aimed to describe the effectiveness of flipped learning with a deep learning framework based on multiple representations in acid–base learning to improve students’ critical thinking skills. The study employed a quasi-experimental method with a nonequivalent control group design. Sampling was conducted using purposive sampling, resulting in class XI F.1 as the experimental class and class XI F.2 as the control class, with 36 students in each class. The experimental class implemented flipped learning through independent learning using videos and contextual texts before classroom instruction, followed by practical work, discussions, interpretation of observations, analysis, drawing conclusions, and reflection in class. The intervention integrated a pedagogical deep learning framework through mindful, meaningful, and joyful learning, as well as learning experiences of understanding, applying, and reflecting, supported by macroscopic, submicroscopic, and symbolic representations. The control class received conventional learning. Critical thinking skills were measured using a pretest–posttest instrument covering interpretation, analysis, and inference, and the data were analyzed using N-gain and the Mann–Whitney U test. The results showed that the experimental class obtained a higher mean N-gain (0.63) than the control class (0.37), with both classes falling into the moderate category. The Mann–Whitney U test showed a significant difference between the experimental and control classes (p < 0,001). These findings indicate that the implementation of flipped learning with a deep learning framework based on multiple representations in acid–base learning is effective in improving students’ critical thinking skills. ]]>
