Middle school mathematics teachers’ concept definitions of geometric objects

Abstract

The aim of this study is to examine middle school mathematics teachers’ concept definitions of five geometric objects (prism, pyramid, cone, cylinder, and sphere). The study was carried out with the participation of 99 mathematics teachers who have been working in middle schools located in three different provinces and districts. The data were gathered through a form consisting of six open-ended questions, which were prepared to reveal the participants’ Concept Definition (CD) of Geometric Objects (GOs). Via content analysis technique, codes from the data and categories from the codes were obtained. Results showed that some of the participants could not make the CDs of GOs correctly, that they generally drew the square or rectangular forms and only included the vertical states of the GOs objects. It was found that participants generally could not establish a relation between “cylinder and prism” and “cone and pyramid”. Evidence was also found that some of the participants saw themselves as inadequate in defining the GOs. On the other hand, it can be said from their explanations and drawings that the teachers’ professional experiences do not have much effect on defining those concepts.