THE EFFECT OF COOPERATIVE LEARNING MODEL TYPE NUMBERED HEADS TOGETHER (NHT) ON STUDENTS ACHIEVEMENT ON SUB TOPIC EXPANSION IN GRADE VII SEMESTER II SMP N 1 TEBING TINGGI A. Y. 2012/2013

The objectives of this research are: (1) To know the students achievement inphysics subject taught by cooperative learning model type numbered headstogether (NHT). (2) To know the students achievement in physics subject taughtby conventional learning model. (3) To know the effect of cooperative learningmodel type numbered heads together (NHT) on students achievement especiallyon sub topic expansion. The type of research was quasi experiment with thepopulation all of student grade VII in SMP N 1 Tebing Tinggi which consist of 9classes. Sample of this research was obtained by technique cluster randomsampling. The sample is VII5 as the experiment class and VII4 as the control class. Experiment class taught by cooperative learning model type Numbered Heads Together (NHT) and control class taught by conventional learning model. The research instrument has 20 questions in multiple choice forms with 4 options, the instrument tested validated. In this research obtained the mean of pre-test in experiment class is 38.15 and in control class is 38.52. After that do the treatment in experiment class taught by cooperative learning model type Numbered Heads Together (NHT) and in control class taught by conventional learning model, and then done the post-test. The mean of post-test in experiment class is 78.15 and in control class was 73.52. In hypothesis testing obtained tcount > ttable that was 2.03 >1.676 at significant level α = 0.05 and dk =52. So, can be concluded that thestudents achievement in experiment class better than in control class. Ha wasaccepted or has effect of cooperative learning model type Numbered HeadsTogether (NHT) on students achievement on sub topic Expansion in Grade VIISMP N 1 Tebing Tinggi academic year 2012/2013.