High School Students’ Development of Mathematical Discourses on Geometric Reflections in Relation to Instruction

The purpose of this study is to explore the development of high school students’ mathematical discourses on the concept of reflection in relation to instruction. participants of this case study were two 10th grade high school students and a mathematics teacher. the data for the study were collected over eight weeks, and consisted of classroom observations and task-based interviews conducted with the students and teacher. we analyzed the data from the perspective of the commognitive framework. our analysis of the students’ discursive development in relation to instruction showed that the teacher’s discourse in the classroom was at a higher level than the students’ discourses, and the discourses of the teacher and his students differed from each other. the students adopted the teacher’s discourse when his discourse was transparent and explicit for them, but the students did not adopt the teacher’s discourse on reflection when particular elements in his discourse remained implicit for them. in order to enhance mathematical communication in the classrooms and support the discursive development of students, teachers need to be aware of their students’ development and make the elements of their discourses transparent in the classroom.