Teaching experiment regarding to improve 11th grade students' conceptions of quadrilaterals

The aim of this study is to determine the readiness of 11th grade students about quadrilaterals and to examine the development of their comprehension of this subject, the difficulties they encounter in the process and their opinions about the process in an instructional environment enriched with the use of tools such as Geogebra, concrete materials and geometry strips and group discussions. In this qualitatively designed study, the teaching experiment method was used. The research was carried out with 6 students attending a private Anatolian High School in Ankara in the 2nd semester of the 2021-2022 academic year. Since the study was conducted outside of class hours, the participants were determined to participate in the teaching experiment on a voluntary basis. The research data consisted of the measurement tool for quadrilaterals, activity sheets and evaluation questions, individual applications of the measurement tool for quadrilaterals, and audio and video recordings of the classroom activities constituting the teaching experiment. Transcripts of the video recordings were created and the data obtained were analyzed and interpreted by the researcher according to the conceptual framework. The measurement tool related to quadrilaterals was administered to the students through individual interviews at the beginning and end of the study, and the teaching experiment process, which included classroom studies, lasted for 5 weeks. The situations observed in the participants during the individual interviews and during the classroom activities were analyzed and interpreted according to Van Hiele geometric thinking levels. In this context, it can be said that the use of tools such as Geogebra, concrete materials and geometry strips and teaching environments enriched with group discussions had a positive effect on students' comprehension of quadrilaterals. Considering the progress made by the students during the study, it is thought that the study will contribute to the teaching of geometry courses at high school level and creating an active learning environment and it will be a useful resource for future studies.