• Communications of Mathematical Education
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• v.30 no.4
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• pp.435-452
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• 2016

This study was designed to explore students' instrumentalization in relation to the van Hiele's teaching method within a technology environment using GeoGebra. To carry out the study, a total of 4 lesson units was developed based on van Hiele teaching method for two slow learners in Gyeonggi province, Korea. The results of study were as follows. Instrumentalization of students was actualized from preparation, to adaptation, and to application stages. In preparation, and adaptation stages, depending on visualization, students used a trial-and-error method a lot, however in application stage the role of GeoGebra was just to check the solution of what they conjectured. Therefore, a teacher should prepare geometric tasks according to the processes of instrumentalization based on geometric teaching method. During instrumentalization and instrumentation of users, usage scheme(US) and instrumented action scheme(IAS) should be concrete.