Examining the skills and levels of defining, classification, discrimination of tetragon and tetragon types of primary school mathematics teacher candidates

Having a mathematical domain language enables the concepts to be learned more meaningfully and accurately by strengthening the relationship between them. In addition, it prevents the memorization of concepts in mathematics education. For this purpose, the answers written by the preservice teachers in the context of quadrilaterals were examined in our study and the skills of teacher candidates to defining, classification and discrimination the skills and levels have been examined. Quantitative research method was used in the research. The universe of the research is the province of Ağrı located in the Eastern Anatolia Region. The easily accessible state sampling type, which is one of the sampling types that will make progress more easily, was preferred. In this context, the sample of the study consists of 61 teacher candidates studying in Ağrı in the 2019-2020 academic year. In line with the purpose of the research, a test of defining, classification and discrimination geometric concepts, which was developed by the researcher and consisted of thre parts, was used. In the Test of Defining, Classification and Discrimination Geometric Concepts (1st Part), preservice teachers were asked to define the concepts of quadrilateral, trapezoid, parallelogram, rhombus, rectangle, and square. In the Test for Defining, Classification and Discrimination Geometric Concepts (2nd Part) 17 different visuals were given to prospective teachers and questions were asked to classification the quadrilateral and quadrilateral types. In the Test for Defining, Classification and Discrimination Geometric Concepts (3nd Part) 17 different visuals were given to prospective teachers and questions were asked to discrimination the quadrilateral and quadrilateral types. As a result of the findings obtained from the research, skills and levels are determined used by the teacher candidates regarding the quadrilaterals, regardless of their success levels and gender. Preservice teachers levels of identification classification and discrimination were analyzed and compared using the Pearson correlation test.It was observed that the pre-service teachers expressed the properties of quadrilaterals incompletely because they ignored concepts such as corner, angle, perpendicularity, and parallelism while making the definitions of quadrilateral and quadrilateral types. It was observed that the pre-service teachers could not distinguish between definition and characteristics and it was observed that the made mistakes in the classification and discrimination part of the test because they did not take into account the conditions of quadrilateral and hierarchy. According to the results obtained, practitioners are recommended to perform activities defınıng, classıfıcatıon, dıscrımınatıon are included in math courses. 2021, 145 pages Keywords: Mathematical, geometry, definition, classification, discrimination ,quadrilateral,