Investigation of theses written about mathematics process skills

Purpose: The aim of this research is to examine the postgraduate theses written on mathematical reasoning, mathematical communication and mathematical association skills, which are known as mathematical process skills, until 2023 in Turkey. For this purpose, the theses written between 2005 and 2023 were examined and the distribution of theses according to mathematical process skills, graduate levels, years, research model, data collection tools, data analysis methods and sample groups was examined. Method: Qualitative research paradigm was adopted in the research and document analysis method was preferred since theses on mathematical process skills were examined. On the National Thesis Center of the Council of Higher Education, 36 post-graduate theses were found in the search made with the words "mathematical reasoning", "mathematical proof" and "mathematical reasoning", 33 postgraduate theses were found in the search made with the words "mathematical communication", "mathematical language" and "mathematical discourse" and 24 postgraduate theses were found in the search made with the words "mathematical association" and "association". A total of 93 postgraduate theses, 21 of which were doctoral and 72 were master's theses, were reached. The data obtained from the theses, which were examined according to the determined criteria, were analyzed with percentage and frequency values and the findings were presented in a table. Results: When the theses reached within the scope of the research were examined according to mathematical process skills, it was seen that the theses written on mathematical reasoning and mathematical communication skills were more than those written on mathematical association skills. When examined according to the graduate levels, it was determined that the master's theses were considerably higher than the doctoral theses. When the theses are examined according to the years they were written, it was seen that the first thesis on the subject was written in 2005 and a great increase was observed in 2019. The highest number of theses were reached in 2019 and 2022. Quali-tative research methods were preferred more than quantitative research methods in the theses examined according to the research model, and the case study among the qualitative research methods was used at a rate of 33.33%, making it the most used research model. Considering the data collection tools, test, interview and scale forms were used the most. When the usage rates of data analysis methods were examined, descriptive analysis, content analysis and t-test were the most preferred methods. Finally, when the distributions in the sample groups were examined, it was determined that the studies were mostly carried out with secondary school students. Conclusion and Suggestions: Among the examined theses, results such as the number of master's theses more than doctoral theses and the selection of secondary school students in the selection of sample groups were obtained. It has been suggested that in doctoral thesis studies it is necessary to focus more on mathematical process skills, to examine the articles as well as the theses in order to obtain a comprehensive result, and to increase the number of studies with different sample groups. Keywords: Reasoning, Communication, Association, Graduate theses, Document re-view