<![CDATA[This study investigates the impact of the ADLX INTROFLEX TERPADU learning design on critical thinking abilities among Grade IX junior high school students, specifically on the topic of plant reproduction systems. ADLX, which stands for Active Deep Learner eXperience, is a pedagogical approach that merges Active Learning with Deep Learning principles, strengthened by four INTROFLEX pillars—Individualization, Interaction, Observation, and Reflection—developed by JSIT (Jaringan Sekolah Islam Terpadu), and operationalized through seven sequential TERPADU phases: Telaah, Eksplorasi, Rumuskan, Presentasikan, Aplikaskan, Duniawi, and Ukhrowi. This research employed a quasi-experimental design using a pretest-posttest control group framework. The experimental group received instruction through the ADLX INTROFLEX TERPADU learning design, while the control group engaged with the Problem Based Learning (PBL) model. Findings revealed that the average posttest score of the experimental group (91.37) surpassed that of the control group (81.10). The normalized gain (N-Gain) for the experimental group reached 0.83, classified as high, compared to 0.62 (medium) for the control group. These results confirm that the ADLX INTROFLEX TERPADU learning design yields superior outcomes in fostering critical thinking competencies among Grade IX junior high school students studying plant reproduction systems. Keywords: ADLX INTROFLEX TERPADU; critical thinking; plant reproduction system; Problem Based Learning; Grade IX; JSIT]]>
