<![CDATA[This research is motivated by the gap between the demands of the Independent Curriculum which emphasizes innovative learning and the availability of PBL-STEM-based teaching tools at SDN 021 Sungai Kunjang. Learning conditions that are still dominated by conventional methods (teacher-centered) have an impact on the lack of active student participation, so it is necessary to develop teaching modules that are able to trigger critical power and integration between disciplines. This study aims to describe the process of developing the science teaching module on human respiratory organ materials and to determine the feasibility level of the product produced. The method used is Research and Development (R&D) by adapting the 4D (Define, Design, Develop, Disseminate) model from Thiagarajan (1974), which in its implementation is limited to the develop stage. The limited trial was carried out on 23 students of class V A. Data collection instruments included expert validation sheets, observation sheets on learning implementation, and student response questionnaires. The results of the study showed a very high level of feasibility, evidenced by the average percentage of validation of subject matter experts of 93.5%, linguists of 91%, and media experts of 90%. In addition, the results of observation of learning implementation reached an average of 94% with the very good category, and the student response questionnaire obtained a score of 83.41% with the very good category. Thus, the PBL-STEM-based science teaching module on human respiratory organ material is declared valid and practical to be used in learning in grade V of elementary school, and is effective as a solution to the need for innovative and contextual teaching tools. ABSTRAK Penelitian ini dilatarbelakangi oleh adanya kesenjangan antara tuntutan Kurikulum Merdeka yang menekankan pembelajaran inovatif dengan ketersediaan perangkat ajar berbasis PBL-STEM di SDN 021 Sungai Kunjang. Kondisi pembelajaran yang masih didominasi metode konvensional (teacher-centered) berdampak pada minimnya partisipasi aktif siswa, sehingga diperlukan pengembangan modul ajar yang mampu memicu daya kritis dan integrasi antar disiplin ilmu. Penelitian ini bertujuan untuk mendeskripsikan proses pengembangan modul ajar IPAS pada materi organ pernapasan manusia serta mengetahui tingkat kelayakan produk yang dihasilkan. Metode yang digunakan adalah Research and Development (R&D) dengan mengadaptasi model 4D (Define, Design, Develop, Disseminate) dari Thiagarajan (1974), yang dalam pelaksanaannya dibatasi hingga tahap Develop. Uji coba terbatas dilakukan pada 23 siswa kelas V A. Instrumen pengumpulan data meliputi lembar validasi ahli, lembar observasi keterlaksanaan pembelajaran, dan angket respon siswa. Hasil penelitian menunjukkan tingkat kelayakan yang sangat tinggi, dibuktikan dengan rata-rata persentase validasi ahli materi sebesar 93,5%, ahli bahasa 91%, dan ahli media 90%. Selain itu, hasil observasi keterlaksanaan pembelajaran mencapai rata-rata 94% dengan kategori sangat baik, serta angket respon siswa memperoleh skor 83,41% dengan kategori sangat baik. Dengan demikian, modul ajar IPAS berbasis PBL-STEM pada materi organ pernapasan manusia dinyatakan valid dan praktis digunakan dalam pembelajaran di kelas V SD, serta efektif menjadi solusi atas kebutuhan perangkat ajar yang inovatif dan kontekstual. ]]>
