Developing A Learning Trajectory for Teaching Set in Secondary Grade

This study aimed to develop a learning trajectory (LT) for teaching sets using Realistic Mathematics Education (RME) approach and to investigate its influence on student ability. The LT was developed through a design research which consisted of a cyclic process of preparing for the experiment, conducting the experiment, and retrospective analysis. The subject of the study was students at grade VII in Padang. Data were collected through direct observation, interview, and check list, videotaping, and analyzing the work of the students. The LT was evaluated through one-to-one and small group evaluation before it be tried out in a test. The whole strategy (emergent modeling) showed the construction and contribution of the students in discovering the concept of sets from the informal to the formal level. It could help the students to reinvent sets concept. Finally, we discovered that the students increased their mathematics creative thinking ability. Keywords—Design Research, Learning Trajectory, RME,