308 PENGARUH MODEL PEMBELAJARAN KOOPERATIF TIPE GROUP INVESTIGATION TERHADAP HASIL BELAJAR SISWA PADA KELAS X SEMESTER 2 SMK NEGERI 1 PANCUR BATU Fransiskus Gultom 1) , Selamat Karo-karo 2) , Hernawaty 3) , Marioga Pardede 4) , Yona Gulo 5) PENGARUH MODEL PEMBELAJARAN KOOPERATIF TIPE GROUP INVESTIGATION TERHADAP HASIL BELAJAR SISWA PADA KELAS X SEMESTER 2 SMK NEGERI 1 PANCUR BATU Oleh: Fransiskus Gultom 1) Selamat Karo-karo 2) Hernawaty 3) Marioga Pardede 4) Yona Gulo 5) Universitas Darma Agung 1,2,3,4) E-mail: fransiskus_gultom2277@yahoo.co.id 1) selamatkaro@gmail.com 2) hernawaty_sihotang@yahoo.co.id 3) mariogafkippardede@gmail.com 4) guloyona@gmail.com 5) ABSTRACT This study aims to determine the significant effect of the Group Investigation cooperative learning model on students' chemistry learning outcomes in the subject matter of Nomenclature of Compounds and Reaction Equations of class X SMK Negeri 1 Pancur Batu. This type of research is a quasi-experimental research (quasi-experimental) to determine whether there is an influence or effect of something that is caused to the subject, namely students. The population of this study were all students of class X Semester 2 of SMK Negeri 1 Pancur Batu which consisted of 4 parallel classes. Sampling was carried out using cluster random sampling technique, namely class X TKJ-1 as an experimental class totaling 32 people who were taught with the Group Investigation Type Cooperative learning model and class XTKJ-2 as a control class totaling 30 people who were taught by direct learning. The instruments in this study consisted of 21 multiple choice questions with 5 options (a, b, c, d, and e) which had been tested for validity, reliability, level of difficulty and discriminatory power. The results of this study obtained that the average pretest value for the experimental class was 32.14 with a standard deviation of 10.89 and for the control class 35.40 with a standard deviation of 14.62. From the results of the t-test for the two parties, tcount = 1.055 and ttable = 1.671 because tcount<ttable (1.055<1.671), it can be stated that the initial abilities of the two classes are the same. Then given a different treatment, at the end of the lesson a post-test was carried out with the results of the average value of the experimental class obtained 78.09 with a standard deviation of 10.64 and the control class with an average value of 63.81 with a standard deviation of 13.90. From the results of the one-party t test obtained tcount = 3.898 and ttable = 1.671 at a significant level α = 0.05 with dk = 60. Because tcount> ttable (3.898 > 1.671), it can be concluded that there is a significant influence of the group type cooperative learning model investigation of student chemistry learning outcomes on the subject matter of Nomenclature of Compounds and Reaction Equations in class X SMK Negeri 1 Pancur Batu. Keywords: Cooperative Learning Group Investigation Type, learning outcomes, and Nomenclature of Compounds and Reaction Equations ABSTRAK Penelitian ini bertujuan untuk mengetahui pengaruh yang signifikan model pembelajaran kooperatif tipe Group Investigation terhadap hasil belajar kimia siswa pada materi pokok