MENGATASI LEARNING OBSTACLE KONSEP TRANSFORMASI GEOMETRI DENGAN DIDACTICAL DESIGN RESEARCH

The purpose of this study was to identify learning obstacle precisely on students' epistemological barriers to the concept of geometry transformation. Furthermore, researchers overcome these obstacles by developing mathematical learning concepts in the concept of geometry transformation in high school. This research was conducted at one of the senior high school in Tangerang Selatan. The research method used is Didactical Design Research. This method is carried out in three stages, the analysis of didactic situations before learning (prospective analysis), metapedidactic analysis, and retrospective analysis. Based on the results of the preliminary study, of the 20 students who took the obstacle learningidentificationtest,82.35%ofthetotalstudentsexperiencedepistemologicalbarrierstotheconceptofgeometry transformation. In overcoming the epistemological obstacles students in the concept of geometric transformation requires the design of learning developed based on learning obstacle analysis, repersonalization, and recontextualization so as to produce hypotheses consisting of Hypothetical Learning Trajectory which contains various activities and predictions of student responses and anticipations and produces Student Worksheets. The results show that the didactic design provided can overcome student barriers. It can be seen from the effectiveness of anticipation given during learning that reaches 90% of the difficulties that arise based on predictions of response and anticipated didactic pedagogical.

Analisis Learning Obstacle Pada Pembelajaran Nilai Tempat Siswa Kelas II SD [Learning Obstacle Analysis on Place Value Learning in Students Class II Elementary School]

The concept of place value is very important taught before student learned addition and subtraction.However, in reality student has learning obstacle when they learn place value. The aim of this research is to analize the student obstacles in 3 digit place value. This research is a qualitative research and involved 50 students of grade 2 elementary school. From the analysis of the data, i.e., student test results and student interview, the result is we found two obstacles, ie.,didactical and epistemological obstacle. Didacticalobstacleis caused by using horizontal representation strategy of place value in 2013 curriculum textbookdid not help student to interpret number from the point of view place value, so that when the student must sum the result of horizontal representation strategy, students only combine the number symbol instead of summing numbers. Another didacticalobstacleis examples and questions about place value in 2013 curriculum book are less varied that indirectly raises epistemological obstacle which lead to examples and questions are given by teacher are not varied.This finding needs to be followed up by conducting development research that can reduce learning obstacle that have been discovered