<![CDATA[ABSTRACT Critical thinking and communication are essential 21st-century competencies that need to be developed among junior high school students, yet both remain challenging to develop through classroom learning. This study aimed to analyze differences in the effects of Project-Based Learning (PjBL) and Problem-Based Learning (PBL) on students’ critical thinking and communication skills, both simultaneously and partially. The study employed a quantitative approach with a quasi-experimental non-equivalent control group design. The sample consisted of 60 eighth-grade students at SMP Negeri 1 Pringgasela, divided into PjBL and PBL groups, with 30 students in each group. Data were collected using an essay test to assess critical thinking and a performance test to assess communication skills, both of which underwent validity and reliability testing. Data were analyzed using Multivariate Analysis of Variance (MANOVA) at a significance level of 0.05. The results showed a significant simultaneous difference between PjBL and PBL in students’ critical thinking and communication skills (Pillai’s Trace = 0.878; F = 205.702; p < 0.05). Partially, PBL was more effective in developing critical thinking, whereas PjBL was more effective in developing communication skills. These findings indicate that learning model selection should be aligned with the competencies targeted in instruction. ABSTRAK Kemampuan berpikir kritis dan komunikasi merupakan kompetensi abad ke-21 yang penting dikembangkan pada siswa SMP, tetapi keduanya masih menghadapi kendala dalam pembelajaran. Penelitian ini bertujuan menganalisis perbedaan pengaruh model Project-Based Learning (PjBL) dan Problem-Based Learning (PBL) terhadap kemampuan berpikir kritis dan komunikasi siswa secara simultan maupun parsial. Penelitian menggunakan pendekatan kuantitatif dengan desain quasi-experimental non-equivalent control group. Sampel terdiri atas 60 siswa kelas VIII SMP Negeri 1 Pringgasela yang terbagi dalam kelompok PjBL dan PBL, masing-masing 30 siswa. Data dikumpulkan melalui tes uraian kemampuan berpikir kritis dan tes unjuk kerja kemampuan komunikasi yang telah melalui validasi dan uji reliabilitas. Data dianalisis menggunakan Multivariate Analysis of Variance (MANOVA) pada taraf signifikansi 0,05. Hasil penelitian menunjukkan terdapat perbedaan pengaruh signifikan secara simultan antara PjBL dan PBL terhadap kemampuan berpikir kritis dan komunikasi siswa (Pillai’s Trace = 0,878; F = 205,702; p < 0,05). Secara parsial, PBL lebih unggul dalam kemampuan berpikir kritis, sedangkan PjBL lebih unggul dalam kemampuan komunikasi. Temuan ini menunjukkan bahwa pemilihan model pembelajaran perlu disesuaikan dengan kompetensi yang menjadi tujuan pembelajaran.]]>
