Prospectıve mıddle school mathematıcs teachers’ use of parameters ın explaınıng geometrıc transformatıons

National and international curriculum documents give emphasis to geometric transformations. In particular, parameters of geometric transformations play crucial role in defining geometric transformations. Thus, it needs to be explored to what extent prospective teachers use parameters in explaining geometric transformations. In this study, qualitative case study methodology was used and participants were sixteen prospective middle school mathematics teachers enrolled in a teacher education program in Turkey. To reveal prospective teachers’, use of parameters in explaining geometric transformations, a transformation geometry activity was designed and implemented. During the implementation of the activity, classroom observations were carried out. The classroom observations focused on participants’ small group discussions and whole class discussions regarding geometric transformation concepts. Moreover, implementation of the activity was audio-taped and video-taped. Participants’ use of parameters was revealed by using written materials and participants’ explanations during the whole class discussions. The findings showed that none of the pairs provided totally correct explanations for geometric transformations. They had partial understanding about the parameters of rotation. Moreover, one of the pairs held incorrect ideas about identification of the angle of rotation...