THE EFFECT OF SCIENTIFIC APPROACH BY USING GROUP INVESTIGATION MODEL IN RESPIRATORY SYSTEM TOPIC GRADE XI ON STUDENT LEARNING ACHIEVEMENT SMAN 5 MEDAN ACADEMIC YEAR 2018/2019

The aim of this study was to determine the effect of Group Investigation learning model on student learning achievement of class XI students on Respiratory System topic in SMAN 5 Medan. The type of research was quasi-experimental. The population consisted of 8 classes with 264 students and sampling technique by random sampling, there two sample class where class XI MIPA 6 (Control class) was 32 students and XI MIPA 7 (Experimental class) was 32 students. The instrument used in collecting data in the form of multiple choice tests consists of 40 questions. From results of data analysis requirement test, both samples are normally distributed and have homogeneous variance. Based on data analysis the average score of student learning achievement in experimental class ( using Group Investigation) is 37,53 in pre-test and 81,09 in post-test, while the average score of student learning achievement on control class ( using Lecture Method) is 40,56 in pre-test and 60,53 in post-test. The t-test result was tcount (6,89) and ttab (1,99932), therefore tcount > ttab, it could be concluded there was an effect of Group Investigation learning model on student learning achievement of class XI students on Respiratory System topic in SMAN 5 Medan Academic Year 2018/2019.