Effects of the dynamic geometry environmkents on 7th grade students' abilities in definitions and classification of quadrilaterals

In this study, it is aimed to examine 7th grade students? the abilities of definitions and classification of quadrilaterals and the abilities of making logical deduction among quadrilaterals in the dynamic geometry environments, and to determine the effect of this environments? role in that reaching van Hiele level 3. In this context, the participants consisted of two experimental groups and one control group, the first experimental group studied with the Geometric Supposer while the second group studied with Cabri Geometry and the control group studied with tangible materials (geo-boards, geo-stripes and dot paper) which are suggested in the curriculum. How students bypass the quadrilateral pairs was questioned via clinical interviews in the qualitative dimension of the study. As quantitative data collection tools, the tests which were developed within the scope of this study and oriented to examine the students? abilities of definitions and classifications of quadrilaterals, making logical deduction and creating hierarchical charts among quadrilaterals; and van Hiele Geometry Test developed by Ususkin (1982) were utilized. Main implementations took approximately two weeks. As the result of quantitative analysis, it was identified that the students studying in the dynamic geometry environments outperformed statistically the students in the control group in defining and classifying the quadrilaterals, making logical deductions among quadrilaterals. On the other hand, all three learning environments remained insufficient to reach van Heile level 3. As for learning the general properties of quadrilaterals, although all of the learning environments were seen to be effective, it was seen that the students who studying with Cabri Geometry outperformed statistically the other groups. As the result of qualitative analysis, it was seen that the students studied in the dynamic geometry environments bypassed the quadrilateral pairs more easily than the control group students did. At the end of the study, the suggestions are given to researchers by taking the consequence of this study into account.