Abstract
This study aims to develop STEM-based e-booklet media to improve elementary school students' critical thinking skills in learning science on the human digestive system. Critical thinking skills are essential for elementary school students because science learning requires them to analyze information, identify relationships, and solve problems based on evidence. However, science learning on the human digestive system can be challenging for students when the learning materials are less engaging and do not sufficiently encourage active thinking and exploration. This study uses the Research and Development (R&D) method with the ADDIE (Analysis, Design, Development, Implementation, Evaluation) development model. The subjects of this study were fifth-grade students and class teachers at SDN Sumbersari 03. The instruments used in the study included expert validation questionnaires, teacher and student response questionnaires, and pretest and posttest tests. The results showed that the STEM-based e-booklet media obtained a feasibility score with a percentage of 100% from media experts, 87.5% from language experts, and 95% from material experts, with a very feasible category. The results of teacher responses obtained a percentage of 100% and student responses 89.07%, with a very practical category. In addition, the results of the pretest and posttest showed an increase in critical thinking skills with an N-Gain value of 0.71 or 71%. Thus, STEM-based e-booklet media is declared feasible, practical, and effective for use in science learning in elementary schools.