Development of Inquiry-Based LKPD to Improve Critical Thinking and Problem Solving Skills of Class IX Students at Junior High School

This research aims to develop an inquiry-based Student Worksheet (LKPD) on crossover material in class IX of SMP Negeri 1 Bungku, using the Research and Development (R&D) model with a 4-D model consisting of the Define, Design, Develop, and Disseminate stages. The research population was all class IX students with a purposive sample of 30 students from class IXA. Research instruments include validation sheets, observation sheets, student response questionnaires, as well as pretests and posttests. Validation by experts shows that the LKPD meets the valid criteria with an average score of 3.7. Readability tests and trials in class IXA show that the teacher's ability to manage learning and student activities meets the minimum criteria of good. Student responses to inquiry-based LKPD were very positive, with a percentage of ≥ 80%. Data analysis using effect size shows a value of 0.95, indicating a large effect of using LKPD on improving students' critical thinking and problem solving skills. Based on research results, inquiry-based LKPD is proven to be valid, practical, and effective in improving students' critical thinking and problem-solving skills.