A teaching experiment on pre-service teachers' reasoning processes in environments enriched with dynamic geometry software

The aim of this study is to evaluate the effect of geometry teaching designed using a dynamic geometry software on the mathematical reasoning and construction processes,the basic geometry content knowledge and the geometry achievement levels of pre-service mathematics teachers, to investigate their understanding of basic geometric concepts and to determine their views and the difficulties they encounter during the teaching experiment. A qualitative teaching experiment model was used in the study. The teaching experiment lasted for 12 weeks covering the Geometry-1 course curriculum involving foundations of Euclidean geometry as an axiomatic system, constructing proves for the basic geometrical theorems, constructing geometric structures with a constructivist approach by using Cabri Geometry Dynamic Geometry Software. The participants of the study involved 68 pre-service teachers who took Geometry-1 class and enrolled at Bursa Uludağ University Mathematics Education Department Undergraduate Degree Programme in the spring semester of 2016-2017 academic year. Data collection tools were multiple choice geometry achievement test, open ended basic geometry content knowledge test, open ended proof interpretation test, open ended proof test, open ended basic geometric construction test, observations and interviews. Semi-structured written open-ended questionnaire and verbal interview techniques were used to examine the students' views on the geometry teaching experiment. Numerical analyses of the data were made by the dependent samples t test. Descriptive analysis techniques were used to analyse the findings of the observations. Content analysis techniques were used for the analysis of the findings of the interviews. Qualitative and quantitative data analysis techniques were used for the analysis of the open-ended tests. The findings are presented with percentage and frequency tables. Pre-tests and observations of the first lessons showed that pre-service teachers' geometry achievement, basic geometry content knowledge, basic geometric construction, geometric reasoning and proof skills were low. The results of the research revealed that the lessons had a significant and positive effect on the aforementioned skills of the pre-service teachers and positively affected the prospective teachers' perspective on the geometry course. Considering the progress made by the pre-service teachers during the study, it is thought that the research will contribute to the instruction methods of undergraduate mathematics courses and give insights to the future research. Being an example and resource for mathematics teachers.