The Development of Student Worksheets (LKPD) in Learning Science through Group Investigation Learning to Train Critical Thinking Skills of Junior High School Students

The purpose of this study is to produce a Student Investigation Worksheet (LKPD) based on Group Investigation learning to train the appropriate Junior High School students’critical thinking skills based on validity, practicality, and effectiveness. LKPD was developed with a 4-D research design namely Define, Design, Develop, and Disseminate. The limited trials were conducted with 30 students. Then, the validity is reviewed from the results of the validation of the RPP and LKPD. The practicality here is reviewed from the implementation of lesson plans (RPP) and the constraints also the activities of students in learning process, and the effectiveness is viewed from the results of the pretest and posttest critical thinking skills and student questionnaire responses. The results of the lesson plans (RPP) category validity are very valid and the reliability is 93%, while the LKPD category validity is very valid and the reliability is 93%. The practicality is reviewed based on the implementation of learning in the excellent category and reliability of 98.8%, the student activity is very enthusiastic. Then, the effectiveness is reviewed from the results of the pretest and posttest which before learning process, none of the students achieved completeness, whereas after 30 trials were declared 22 was completed and 8 incomplete based on the N-Gain calculation the average yield was 0.94 with high criteria. The student responses showed an interest in LKPD of 92.68% in the very effective category. LKPD that has been developed is valid, practical, and effective. So, it is appropriate to practice the critical thinking skills of junior high school students. Keywords—worksheet (LKPD), group investigation, critical thinking skills