%A NIM.: 20104040029 Dela Agus Tyani %O Pembimbing: Suparni, S.Pd., M.Pd. %T EFEKTIVITAS MODEL REALISTIC MATHEMATICS EDUCATION (RME) DENGAN METODE GROUP INVESTIGATION (GI) TERHADAP KOMUNIKASI MATEMATIS DAN KEAKTIFAN SISWA %X This study aims to determine the effectiveness of the Realistic Mathematics Education (RME) model with the Group Investigation (GI) method in mathematics learning for class VII of SMP Negeri 01 Kaloran, Temanggung. By implementing this learning model, it is expected to improve students' mathematical communication skills and activeness, especially in the material of lines and angles. This type of research is quasi-experimental with a nonequivalent control group design. The variables in this study consist of independent variables, namely the Realistic Mathematics Education (RME) model with the Group Investigation (GI) method and the dependent variables in this study are students' mathematical communication skills and student activeness. The population in this study were all students of class VII of SMP Negeri 01 Kaloran Temanggung in the 2023/2024 academic year. The sample in this study was class VII E and VII F. The instruments in this study were pretest-posttest questions on students' mathematical communication skills, prescale-postscale student activeness, and teaching modules. The data analysis technique in this study used the parametric t-test for students' mathematical communication skills and activeness. Data analysis was carried out using SPSS 26 software. The results of the study showed that the results of the independent sample t-test on the posttest data of students' mathematical communication from the value (sig.(2-tailed))/2 was 0.005 and the value (sig.(2-tailed))/2 postscale of student activity was 0.002 where both a<0.05 (H0 was rejected) which means that mathematics learning using the Realistic Mathematics Education (RME) model with the Group Investigation (GI) method is more effective than conventional learning on students' mathematical communication skills and activity. %K Realistic Mathematics Education, Group Investigation, Komunikasi Matematis, Keaktifan %D 2024 %I UIN SUNAN KALIJAGA YOGYAKARTA %L digilib67063