<![CDATA[Creative thinking is one of the essential twenty-first-century competencies that should be developed in science learning. However, students' creative thinking skills remain relatively low because classroom instruction is often teacher-centered and provides limited contextual learning experiences. One learning alternative to address this issue is Ethno-STEM-based Project-Based Learning (PjBL), which integrates project-based activities with local wisdom. This study aimed to analyze the effect of the Ethno-STEM-based Project-Based Learning model on students' creative thinking skills in the topic of interactions among living organisms and their environment. This study employed a quantitative approach using a quasi-experimental method with a nonequivalent control group design. The research sample consisted of two Grade VII classes from a junior high school in Lebak Regency, selected using cluster random sampling, with Class VII E (n=30) serving as the experimental group and Class VII C (n=30) as the control group. The research instruments included a creative thinking skills test, learning implementation observation sheets, product design assessment sheets, and student response questionnaires. Data were analyzed using normality and homogeneity tests, an independent sample t-test, N-Gain analysis, and effect size analysis. The results indicated that the experimental class achieved a higher posttest mean score (82.13) than the control class (73.53). The average N-Gain score of the experimental class was 0.683 (moderate category), exceeding that of the control class (0.431). The independent sample t-test produced a significance value of 0.000 (p<0.05), indicating a statistically significant difference between the two groups. Furthermore, the effect size value (Cohen's d) of 1.630 indicated a high practical effect of the implemented learning model. Product assessment results, learning implementation, and students' responses also fell within the very good category. Therefore, the Ethno-STEM-based Project-Based Learning model has a significant and substantial effect on improving students' creative thinking skills in learning the topic of interactions among living organisms and their environment. ABSTRAK Kemampuan berpikir kreatif merupakan salah satu kompetensi penting abad ke-21 yang perlu dikembangkan dalam pembelajaran IPA. Namun, kemampuan berpikir kreatif peserta didik masih tergolong rendah karena pembelajaran cenderung berpusat pada guru dan kurang memberikan pengalaman belajar yang kontekstual. Salah satu alternatif yang dapat diterapkan adalah model Project-Based Learning (PjBL) berbasis Etno-STEM yang mengintegrasikan pembelajaran berbasis proyek dengan kearifan lokal. Penelitian ini bertujuan untuk menganalisis pengaruh model Project-Based Learning berbasis Etno-STEM terhadap kemampuan berpikir kreatif peserta didik pada materi interaksi makhluk hidup dan lingkungannya. Penelitian menggunakan metode kuantitatif dengan desain quasi-experiment tipe nonequivalent control group design. Sampel penelitian terdiri atas dua kelas VII di salah satu SMP di Kabupaten Lebak yang dipilih menggunakan teknik cluster random sampling, yaitu kelas VII E (n=30) sebagai kelas eksperimen dan VII C (n=30) sebagai kelas kontrol. Instrumen penelitian meliputi tes kemampuan berpikir kreatif, lembar observasi keterlaksanaan pembelajaran, lembar penilaian rancangan desain produk, dan angket respons peserta didik. Data dianalisis menggunakan uji normalitas, uji homogenitas, uji independent sample t-test, perhitungan N-Gain, dan effect size. Hasil penelitian menunjukkan bahwa rata-rata nilai posttest kelas eksperimen (82,13) lebih tinggi dibandingkan kelas kontrol (73,53). Nilai rata-rata N-Gain kelas eksperimen sebesar 0,683 berada pada kategori sedang dan lebih tinggi dibandingkan kelas kontrol sebesar 0,431. Hasil uji independent sample t-test memperoleh nilai signifikansi 0,000 (p<0,05) yang menunjukkan adanya perbedaan signifikan antara kedua kelas. Besarnya pengaruh penerapan model ditunjukkan oleh nilai effect size (Cohen's d) sebesar 1,630 yang termasuk kategori tinggi. Selain itu, penilaian rancangan desain produk, keterlaksanaan pembelajaran, dan respons peserta didik menunjukkan kategori sangat baik. Dengan demikian, model Project-Based Learning berbasis Etno-STEM berpengaruh positif dan signifikan dalam meningkatkan kemampuan berpikir kreatif peserta didik pada materi interaksi makhluk hidup dan lingkungannya. ]]>
