THE EFFECT OF LEARNING GEOMETRY BASED ON VAN HIELE THEORY WITH MIND MAPPING TECHNIQUE ND DIRECT INSTRUCTION TO STUDENTS’ SPATIAL ABILITY IN SMP N 4 BALIGE A.Y 2017/2018

This research aimed to determmie: 1) students’ spatial ability by using geometry learig based on Van Hiele theory with mind mapping technique is better tha sutudents who taught geometry by direct instruction. 2) there wasn’t the interaction between learning and students’ mathematical initial ability to students’ spatial ability. This research was quasi experiment. The populations of this research were all the students in eigth grade of SMP Negeri 4 Balige and the sample was choosen randomly which were VIII-1 as experiment class and VIII-2 as controlling class, each consist of 31 students. The instrument used consist of :1) mathematical initial ability test, 2) spatial ability test, the subject was about cuboid and rectangle prism. The instrument has been decared eligible content validity and reliability coefficient of 0,6102 for the students’ spatial ability. The analyse of data were done by using ANAVA two-ways. The result of this research shown that (1) students’ spatial ability based on Van Hiele theory with mind mapping technique was better than students who taught learning geometry by direct instruction, (2) there was interaction between learning and students’ mathematical initial ability toward students’ spatial ability. The researcher suggest to use the geometry learning based on Van Hiele theory with mind mapping technique as the alternative way for teachers to develop students’ spatial ability.