Penelitian ini bertujuan untuk menghasilkan bahan ajar science story (BASS) berbasis inquiry yang layak (valid, praktis, dan efektif) dan dapat meningkatkan kecakapan berpikir peserta didik Sekolah Dasar dengan pengembangan menggunakan model 4-D yang diujicobakan pada tiga SD di Gresik pada semester genap tahun ajaran 2018/2019 dengan one-group-pretest-postest design. Analisis data menggunakan deskriptif kuantitatif dan kualitatif. Hasil penelitian menunjukkan BASS berbasis inquiry yang dikembangkan layak yaitu: 1) valid (skor rata-rata 3.3), 2) praktis yang meliputi aktivitas peserta didik dan keterlaksanaan RPP kategori sangat baik, 3) efektif dengan hasil belajar 96% tuntas dan respon siswa positif (kategori sangat baik). Simpulan penelitian bahwa pengembangan bahan ajar science story berbasis Inquiry layak, yang meliputi valid, praktis dan efektif dan meningkatkan kecakapan berpikir mengolah informasi dalam pembelajaran IPA di Sekolah Dasar.

This study aims to produce inquiry-based science story (BASS) teaching materials that are feasible (valid, practical, and effective) and can improve the thinking skills of elementary school students by using 4-D model development that is tested in three elementary schools at Gresik in the even semester. 2018/2019 school year with one-group-pretest-posttest design. Data analysis using quantitative and qualitative descriptive. The results showed that inquiry-based BASS that was developed is feasible, namely: 1) valid (average score 3.3), 2) practical which included the activities of students and the implementation of lesson plans in very good categories, 3) effective with 96% learning outcomes completed and positive student responses (very good category). Conclusion of the study that the development of Inquiry-based science story teaching materials is feasible, which includes valid, practical and effective and improves thinking skills especially processing information aspect in science learning in elementary schools.