PENGEMBANGAN DAN KELAYAKAN LKPD BERBASIS STEM PADA MATERI EKOSISTEM UNTUK MENINGKATKAN KETERAMPILAN BERPIKIR KRITIS SISWA SEKOLAH DASAR

This study aimed to develop and examine the feasibility and practicality of a Student Worksheet (LKPD) based on Science, Technology, Engineering, and Mathematics (STEM) on Ecosystem topics oriented toward elementary school students' critical thinking skills. The development procedure applied a Research and Development (R&D) method using the ADDIE model encompassing Analyze, Design, Development, Implementation, and Evaluation stages. The research was conducted at MIS Ad-Dakwah Kabanjahe during the even semester of the 2025/2026 academic year, involving 25 fifth-grade students and three classroom teachers. Data collection instruments comprised expert validation rating sheets and user practicality questionnaires. Validation results demonstrated that the product was in the highly feasible category, with scores of 90.59% from subject-matter experts, 90.00% from media design experts, 89.00% from language experts, and 91.00% from test instrument experts. Practicality testing showed a highly practical qualification, reaching 90.00% in individual trials, 94.00% in small-group trials, 92.00% in large-group trials, and 90.00% from teacher responses. Therefore, the STEM-based LKPD on Ecosystems is declared highly feasible and practical for facilitating critical thinking activities in elementary science education.