Abstract:

This research was carried out to evaluate the effectiveness of the training program designed to improve proof skills with the dynamic geometry software GeoGebra on the nonverbal proof making skills of mathematics teachers and teacher candidates. Due to the use of various quantitative and qualitative data collection tools in the research, the sequential explanatory method, one of the mixed research methods, was used. The study was conducted with a total of 41 participants, including 35 3rd grade mathematics teacher candidates studying in Mathematics Education at a state university in a city in the Central Black Sea Region in the 2019-2020 academic year, and 6 mathematics teachers doing a master's degree in Mathematics Education. A five-week GeoGebra nonverbal proof skills development training was held with the participants and a study group was formed by selecting 9 volunteer participants. The data of the research consists of the answers given by the participants to the proof skill test, the camera recordings taken during the GeoGebra training process, the evaluation forms and the interviews made with the audio recordings. As a result of the quantitative findings of the study, a significant difference was found between the pre-tests and post-tests of the participants in favor of the post-test. For this reason, it is possible to say that the training program designed to develop proof skills with GeoGebra, a dynamic geometry software, supports the development of nonverbal proof skills of mathematics teachers and teacher candidates. In addition, it was concluded that this training program, which was designed to develop proof skills with GeoGebra, improved the proof skills of mathematics teachers statistically significantly more than the proof skills of prospective teachers.

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