Investigation of secondary school students' learning processes of geometric concepts through tessellations in dynamic geometry environments

The general purpose of this research is to examine the development of secondary school 8th grade students' various geometric concepts through geometric decorations created in dynamic geometry environments. In this qualitative study, the teaching experiment model was used. The research was conducted with 15 students from a public middle school located in a socio-economically mid-to-low-level area in Akşehir, a district of Konya. Among these students, seven students were selected as focus participants. Semi-structured interviews were conducted with the focus participants before the application. Within the scope of the study, the students were first introduced to the GeoGebra dynamic geometry program, which lasted 5 weeks. Then, students were taught about decorations for 15 weeks. In the teaching carried out in the computer laboratory accompanied by worksheets, students are first asked to examine the ornament photo. Then, students are expected to create the ornament with pattern blocks and construct it in GeoGebra. The student who draws the last ornament on dotted/isometric paper is asked to state the repetition unit in the ornament, the relationship between angles at a corner point and the transformations in the ornament. At the end of each teaching session, the student is required to keep a diary about that day's process. During the teaching sessions, classroom video recordings and computer video recordings of the focus students are taken. In addition, the researcher, who conducts the teaching processes, keeps a weekly diary. In this way, possible data loss has been reduced. In the 14th week, a field trip activity was held in which students would identify and build an example of decoration from their living spaces. This teaching week, students were expected to establish a connection between mathematics and culture. Students walked around the historical streets of Akşehir, identified examples of decorations and built their decorations on the computer. In the 15th week, students tried to build an original decoration. At the end of the teaching process, final interviews were held with the focus students. When the pre-interview and post-interview data of the students were compared, it was seen that their conceptual knowledge improved after the application, they mostly eliminated their deficiencies in creating polygons, and progress was made in their geometric transformation knowledge and ornament analysis processes. Keywords: Tessellations, Ethnomathematics, Teaching experiment, Dynamic geometry software.