STUDENT’S CRITICAL THINKING ABILITY WITH THE IMPLEMENTATION OF CASE BASED LEARNING ON HUMAN REPRODUCTIVE SYSTEM MATERIAL IN CLASS IX AT SMP NEGERI 17 MEDAN

This research was motivated by the low critical thinking skills of class IX students at SMP Negeri 17 Medan. The aim of the research is to determine the application of the case based learning model, the differences in students' critical thinking abilities with the application of the case based learning model and conventional learning and to increase students' critical thinking abilities with the application of the case based learning model. The type of research chosen is quantitative descriptive research. The population in this study was all 8 class IX students. The sample in this study consisted of two classes, namely classes IX-8 and IX-7. This sampling technique was carried out randomly by drawing lots. The instruments used in this research were non-tests (learning implementation observation sheets) and tests of students' critical thinking abilities on the human reproductive system material. The results of the research show that the implementation of case-based learning on human reproductive system material in class IX-8 of SMP Negeri 17 Medan was carried out well. The results of the implementation of case based learning obtained 92 results in the very good category. Overall, there is a difference in the achievement of critical thinking skills of students who are taught using the case based learning model with students who are taught the conventional model on indicators of focus, reason, inference, situation, clarity and overview. The critical thinking abilities of students who are taught using the case based learning model are higher than students who are taught using the conventional model, especially in the indicators of focus, reason, inference, situation and clarity. The increase in students' critical thinking skills in the human reproductive system material in class IX of SMP Negeri 17 Medan is in the high category (75%) in classes taught using case based learning. Meanwhile, the class is classified as medium conventional (65%).