Examination of postgraduate thesis studies on teachers working in the field of special education in Turkey (2000-2020)

The aim of this research was to examine graduate thesis studies conducted in the field of special education in Turkey about special education teachers in terms of various variables. In the thesis scanning center of the Council of Higher Education Center (YOK), it was determined that 89 graduate thesis studies in the special education field were conducted. Yet, due to the reason that six of them did not have access permissions, 83 graduate thesis studies were examined. Of the postgraduate thesis examined, 79 of them are master's and four are doctoral dissertations. As a result of the research, it was determined that most of the graduate thesis studies were conducted in 2019. Moreover, when the distribution of universities is examined it has been observed that most of the graduate thesis were studied at Necmettin Erbakan University and Marmara University, and most of the thesis advisor titles are Assist. Prof. Dr. It was concluded that most of the postgraduate thesis were carried out in the Special Education Department and when the methods used in the studies were examined, it was noted that the quantitative method was preferred the most. Considering the research models used in the studies, it was concluded that the correlational survey model was used the most and the sources used in the graduate thesis were mainly domestic sources.


INTRODUCTION
Teachers intend to leave positive and permanent marks in children's lives, to ensure the harmony of their students with the environment, and to establish a strong bond with the school, family, and society. Although special education teachers also have different characteristics in the lives of children with special needs [1], they contribute to children's development in various ways and create a certain educational process so that they can adapt to the established order. In this process, general education services offered to individuals with special needs are insufficient and special education services are needed [2]. Individuals who show significant differences at the level expected from their peers in terms of educational competencies and individual characteristics created in this framework and therefore need special education, should receive training from specially trained teachers. The individuals in question should also receive training in specially prepared training programs and in educational environments adapted to the disability of the individuals [3].
Special education is the name given to all educational services that support individuals' independence and productivity throughout their life and prevent inadequacies from becoming obstacles [3]. The main objective of special education is to minimize the difficulties experienced by individuals in their are newly introduced to scientific research important information about the methods used, topic choices, general trends, and resources used. Researchers who follow such disciplines may have the impression of taking new approaches to their research or developing their previous approaches. Therefore, in this study, which examined the postgraduate thesis studies on teachers working in the field of special education in Turkey, all postgraduate thesis that are in the thesis center of CoHE on teachers working in the field of special education have been taken into consideration, and a general perspective has been created on the field of special education.
In accordance with the purpose of this overview, the following sub-goals have been sought: i) What subjects have been studied for postgraduate thesis studies on teachers working in the field of special education?; ii) What is the distribution of postgraduate thesis studies in Turkey related to teachers working in the field of special education by universities?; iii) What is the distribution of postgraduate thesis studies in Turkey related to teachers working in the field of special education by year and level?; iv) What is the distribution of postgraduate thesis studies in Turkey related to teachers working in the field of special education according to the titles of thesis advisors?; v) What is the distribution of postgraduate thesis studies in Turkey related to teachers working in the field of special education according to the Department?; vi) What is the numerical distribution of methods used in postgraduate thesis studies in Turkey involving teachers working in the field of special education?; vii) What is the distribution of the methods used in postgraduate thesis studies in Turkey related to teachers working in the field of special education according to the research models?; and viii) What is the numerical distribution of domestic and foreign resources used in postgraduate thesis in Turkey on teachers working in the field of special education?

RESEARCH METHOD 2.1. Research model
The topics of the postgraduate thesis on each special education teachers included in the study were examined separately as sub-categories; The headings that were created by combining these topics were reviewed as general categories. Quantitative data was obtained by using the SPSS 22 program in the analysis of the data. Calık and Sozbilir [20] stated that the themes, codes, and dimensions included in content analysis should be visualized and presented by illustrating them in the form of tables, diagrams or graphics. Thus, the data obtained in this study are presented by transforming them into percentage tables (%), frequency (f) and column tables.
This research was conducted using the document analysis technique which is one of the qualitative research methods. Qualitative research allows a comprehensive study of existing situations. This study conducted with the document analysis technique, it is also defined as bibliometric research. Bibliometric studies are studies that allow research to be analyzed by different methods and evaluated by scientific studies. Bibliometric research helps to create forward-looking science policies by evaluating the publishing qualifications of departments, the number of publications, publication qualities, and the selection of the indexes of the journals published [21].

Population and sample
Along with its subheadings working in the field of special education and teaching for the mentally handicapped, all keywords related to teachers working in the field of special education were searched and 89 postgraduate thesis published in National Thesis Center of Higher Education Council of Turkey, CoHE's Thesis Screening Center (YOK) were found. However, because of not allowing access by the authors of six thesis, a total of 83 postgraduate thesis studies on teachers working in the field of special education were analyzed.
From the beginning to the end of the data collection process, it was decided to examine postgraduate thesis studies on teachers working in the field of special education without a year limit and it has been continued in this way. Yet, it could not be included in the study due to the closure of access by the authors of 6 postgraduate thesis on teachers working in the field of special education at the national thesis center. The thesis subjected to examination were obtained from the national thesis center of CoHE (YOK) during the period between December 15, 2020-February 15, 2021. The distribution of these acquired thesis by years and levels is shown in Table 1.  's Doctorate  2000  1  -2013  4  1  2001  1  -2014  3  1  2006  1  -2015  5  -2007  5  1  2016  5  -2008  2  1  2017  6  -2009  3  -2018  13  -2010  3  -2019  22  -2011  1  -2020  3  -2012 1 -Sum total 79 4

Collection and analysis of data
In this study, 89 thesis on teachers working in the field of special education were reached. While 83 of 89 thesis were made available at National Thesis Center of Higher Education Council of Turkey, CoHE Thesis Screening Center, 6 thesis were not accessible because they were closed to access by the author. There were 83 thesis that can be accessed in this study were examined by downloading them from the CoHE Thesis Screening Center on 15.12.2020 -15.02.2021. Also, the data obtained from the research were analyzed using document analysis and content analysis techniques. Content analysis, which is one of the frequently preferred techniques in qualitative studies, acts as a bridge between the analysis of the material and the statistical results by specifying the properties and meanings of some texts numerically [6]. Content analysis; According to Yıldırım and Simsek [21], it is one of the techniques mostly used in social sciences. It is defined as a repeatable, systematic technique in which some words in the texts are summarized into more reduced content categories with codings parallel to the rules within certain rules. In this study, the literature was examined and the opinions of 5 experts, including three special education experts and two non-field experts, were consulted. At the same time, peer opinions were taken before the study and during the analysis process. The data obtained were examined and analyzed by three different experts. Recommended to gain the reliability of scoring among experts; Cavkaytar's [22] "consensus" and "dissensus" formula was used at the forefront (1).

100
(1) As a result of this formula, it is stated that if it is at least .70, reliability will be ensured among the evaluators. The reliability coefficient between experts who analyzed the study was calculated as .87. A total of nine categories were specified in the analysis process of the examined thesis. The results were tabulated and added to the findings section. In the first stage of the document analysis, the master's, and doctoral thesis in the sample group and without access restrictions were downloaded in pdf format on December 15, 2020-February 15, 2020 and transferred to the computer environment. In the second stage, 83 postgraduate thesis to be examined were analyzed by separating them according to years and theme distributions. In the last stage, the data were analyzed, and the findings were interpreted. The analyzed data were divided into themes in line with the sub-problems of the study and added to the findings section in tables.

RESULTS
The discussion can be made in several sub-chapters. In this study, which was conducted to examine postgraduate thesis studies in Turkey on teachers working in the field of special education in terms of various variables, the following findings were found. This section includes the findings of the study and the findings of the data analyzed in line with the purpose and sub-goals of the study. The findings regarding the distribution of the postgraduate thesis on teachers working in the field of special education, which is the first sub-problem of the study, according to their subjects are shown in Table 2 (see Appendix).
In Table 2, subject distributions, percentages, and frequency values of the postgraduate thesis studies on teachers working in the field of special education examined within the scope of the research are indicated. When the subject distribution of the postgraduate thesis is examined; The relationship between the level of burnout and professional knowledge/skills was given to examine the most burnout levels in terms of some variables among the studies collected under the theme of 20 (24.18%).The relationship between the levels of burnout and professional self-esteem, the relationship between burnout syndrome and empathic tendency levels, the relationship between burnout, self-efficacy and empathic tendency levels and sociodemographic characteristics were also included. It is observed that one postgraduate thesis study has been done from each of the other postgraduate thesis topics gathered under this theme. When we look at the studies gathered under the theme of attitude six (7.20%) towards education and assistive technologies, it is seen that one postgraduate thesis was conducted from each subject. Looking at the theme of opinion on the competence of field knowledge, 16 (19.23%); Among the postgraduate thesis topics gathered under this theme, it is clear that most of the studies have been conducted on the evaluation of professional competencies and opinions on professional skill competencies.
When we look at the theme of teachers' cooperation with families and other teachers two (2.40%), it is seen that one postgraduate thesis study has been conducted from each subject. When the relationship between teachers' self-efficacy perceptions and knowledge/skills five (6.04%) theme is examined, it is observed that most of the postgraduate thesis was conducted on the examination of self-efficacy perceptions and anxiety and burnout levels. Looking at the theme five (6%) of determining the problems faced by teachers in education and students, it is seen that one postgraduate thesis is conducted from each subject under this theme. It is seen that among the graduate thesis study subjects gathered under the theme of seven (8.44%) determining the relationship with effective leadership characteristics of teachers, most of the postgraduate thesis studies were conducted on the subject of examining the leadership characteristics of school principals.
When examining the job satisfaction of teachers and looking at the theme six (7.27), it is observed that most of the postgraduate thesis studies were conducted on the examination of the levels of job satisfaction, job satisfaction and professional burnout. When the effectiveness of the methods used by the teachers is examined at theme three (3.60%), it is seen that one postgraduate thesis study has been conducted from each of the postgraduate thesis subjects gathered under this theme. Looking at the theme of determining the relationship with psychological resilience, which is theme two (2.40%), it is observed that one postgraduate thesis study has been conducted from each of the postgraduate thesis subjects collected under this theme. The effectiveness of the developed program or the prepared plan according to the needs of the teachers which is theme two (2.40%), it is seen that one postgraduate thesis study is made from each of the postgraduate thesis subjects collected under this theme.
When we look at the theme of determining the relationship with the empathic tendency levels of teachers which is theme two (2.40%), it is seen that one postgraduate thesis study has been made from each of the postgraduate thesis subjects collected under this theme. It is seen that seven (8.44%) of the postgraduate thesis studies gathered under the Other theme, most of the postgraduate thesis work was done on the evaluation of themselves in terms of professional ethical values. It is observed that one postgraduate thesis study has been done from each of the other postgraduate thesis topics collected under the Other theme. Considering the distribution of the subject of the postgraduate thesis studies on special education teachers in general, it is seen that the most postgraduate thesis studies were conducted on the relationship between burnout and professional knowledge/skills and the subject of field knowledge competence. The second subproblem of the research is "working in the field of special education teachers and postgraduate thesis on the subject of Turkey to the distribution by the university" for the findings are presented in Table 3. The distribution of postgraduate thesis studies on special education teachers according to universities is examined in Table 3. It is seen that the highest number of postgraduate thesis studies were found at Marmara University nine (10.8%) and Necmettin Erbakan University nine (10.8%) and these two universities observed to have an equal distribution. Then, postgraduate thesis studies were intensively found at the following universities: Eskisehir Anadolu University eight (9.6%), Gazi University six (7.2%), Abant İzzet Baysal University four (4.8%), Beykent University three (3.6%), Gaziantep University three (3.6%), Ankara University two (2.4%), Canakkale (18th March) University two (2.4%), Istanbul Sabahattin Zaim University two (2.4%), Maltepe University two (2.4%), Okan University two (2.4%) and Near East University two (2.4%). The findings regarding the distribution of postgraduate thesis studies on special education teachers, which is the third sub-problem of the research, by years and levels are shown in Table 4. When looking at the postgraduate thesis studies on special education teachers in Table 4; It is seen that 79 postgraduate thesis studies were conducted at the master's level and four postgraduate thesis studies were conducted at the doctoral level. Considering the distribution of postgraduate thesis by years and levels; It is seen that three (3.6%) postgraduate thesis studies were made in 2020, and the most postgraduate thesis was made in 2019, which is equal to 22 (26.5%). As a result of the research, it was found that 13 (15.7%) master's thesis in 2018, six (7.2%) master's thesis in 2017, five (6.0%) master's thesis in 2016, five (6.0%) master's thesis in 2015 have been done.
When we look at the year 2014, three master's, one (4.8%) doctoral level thesis were carried out and in 2013, four master's thesis, one doctoral level thesis (6.0%) were conducted. In 2012, it is seen that one (1.2%) thesis at master's level was conducted. On the other hand, in 2011, it is seen that one (1.2%) master's thesis has been done while this number is three (3.6%) in 2010. At the year of 2009, it is observed that three (3.6%) master's thesis have been done. Looking at the year of 2008, it is seen that two master's, one (3.6%) doctoral level thesis work was conducted and in 2007 five master's and one doctorate thesis work (7.2%) was carried out. Finally, looking at the years of 2006, 2001 and 2000, it is observed that only one (3.6%) master's thesis in each year was done. In postgraduate thesis on special education teachers, It is seen that master's level thesis are studied more predominantly than doctoral thesis. In 2019, there is a significant increase in the postgraduate thesis studies on special education teachers compared to the previous years. The findings related to the fourth sub-problem of the research, "distribution of graduate thesis according to advisor titles", are shown in Table 5. When the postgraduate thesis on special education teachers are examined according to their advisor titles in Table 5, it is observed that 20 (24,1%) people with the title of Prof. Dr., 19 (22,9%) people with the title of Assoc. Prof. Dr., 26 (31,3%) people with the title of Assist. Prof. Dr., 18 (21,7%) people with the title of Dr. have provided advisory for postgraduate thesis studies. The findings of the fifth sub-problem of the research "the department that postgraduate thesis are conducted" are shown in Table 6. Table 6. Distribution of postgraduate Thesis by department Considering the department where postgraduate thesis on special education teachers are conducted, it is observed that the most graduate thesis were conducted in the special education department which is 31 (37.3%) and 13 (15.7%) in the department of educational sciences. Subsequently, postgraduate thesis from primary education department were five (6.0%), four (4.8%) from education administration and control department, four (4.8%) from business administration department, four (4.8%) from psychology department, three (3.6%) from basic education department, three (3.6%) from fine arts education department, three (3.6%) from public health department and two (2.4%) from visually impaired education department. In postgraduate thesis studies, it can be said that there are studies in which different disciplines work together according to the subjects of the thesis or examine the variables regarding the subjects related to different two main disciplines.
When we look at other departments it is seen that one, (1.2%) study in the department of information technologies, one (1.2%) study in the department of child development and education, one (1.2%) study in the department of education programs and education, one (1.2%) study in the department of education management inspection planning and economics was conducted. It is indicated that one postgraduate thesis (1.2%) in the department of nursing, one (1.2%) postgraduate thesis in the department of clinical psychology, one (1.2%) postgraduate thesis in the department of mathematics and science education, one (1.2%) postgraduate thesis in the department of applied behavior analysis in autism, one (1.2%) postgraduate thesis in the department of psychiatry, one (1.2%) postgraduate thesis in the department of sociology, and lastly one (1.2%) postgraduate thesis in the department of teaching for the mentally disabled was conducted. Based on the subjects of postgraduate thesis studies on teachers working in the field of special education and the relationship of these studies with the department of special education, it can be indicated that the postgraduate thesis studies on teachers of this field in question was conducted in their related department. Namely, the department of special education. The findings regarding the distribution of "research methods used in postgraduate thesis on special education teachers", which is the sixth sub-problem of the study, are shown in Table 7.
In Table 7, the distribution of 83 postgraduate thesis conducted on special education teachers by their method is examined; It is seen that the quantitative method 55 (66.3%), the qualitative method 22 (26.5%), the mixed method 5 (6.0%) and 1 (1.2%) single-subject research method were used. It is observed that the quantitative method is used the most, and the single-subject research method is the least. It can be stated that the use of the quantitative method at most in the examined 83 graduate thesis depends on the preference and the relationship of the method to be chosen in parallel with the research subject. The findings of the seventh sub-problem of the research, which is the distribution of the methods used in the postgraduate thesis on special education teachers according to the research models, are shown in Table 8. Based on the single-subject research method, it can be clearly said that the least used model compared to other models is adapted alternating treatments design, which is not preferred much depending on the research methods used in the postgraduate thesis studies on special education teachers. The findings related to the eighth sub-problem of the study, "the distribution of domestic and foreign resources used in postgraduate thesis studies on special education teachers" are shown in Table 9. When the references of the postgraduate thesis on special education teachers are examined in Table  9, it was found that 5,693 (68.02%) domestic resources and 2,676 (31.98%) foreign resources were used in master's thesis. When the references sections of master's thesis are examined, it is seen that the preference of domestic sources is more than foreign sources. It can be claimed that the fact that the use of domestic resources is higher than the use of foreign resources is due to the reason that some universities do not require foreign language score criteria in their postgraduate admission requirements.
In Table 9, the references section of doctoral thesis on special education teachers was examined and it was found that 383 (59.47%) domestic resources and 261 (40.53%) foreign resources were used. Looking at the references of doctoral dissertations, it is observed that domestic sources are used more than foreign sources as in master's thesis. When the references section of 83 graduate thesis on special education teachers is examined, it is seen that there are 6,076 (67.41%) domestic resources and 2,937 (32.59%) foreign resources. When examining the references of postgraduate thesis, it is determined that the domestic resources used in master's and doctoral dissertations are more than foreign resources.

DISCUSSION
Considering the distribution of the topics of the postgraduate thesis on special education teachers, it is determined that the most frequently studied subjects were the relationship between burnout and professional knowledge/skills, and opinion on the competence of subject matter knowledge. In the subject distribution of the postgraduate thesis about the teachers working in the field of special education; at most, it is the examination of the relationship between burnout and professional knowledge/skills, and the examination of different variables that develop and affect burnout, which is the result of the inability to cope with stress effectively. It can be assumed that the excessive work in these areas is due to the thought that the burnout that occurs as a result of the reflection of the energy and power of the individuals on the internal resources can be experienced more in the special education teachers. It can also be said that the reason and consequences of this effect may have led to more work on addressing the relationship between burnout and professional knowledge/skills.
The field of special education is a process in itself. In this process, the researchers are asked to evaluate the teachers' views on this field from different perspectives about the education curriculum of special education teachers, the type of skills to be acquired, and the usefulness of the services provided [24]. It can be said that the fact that the sensitivity and importance of these issues are known by the researchers may cause frequent studies on the field of opinion on the adequacy of the field, as in the case of burnout. In addition, the general similarity of the topics in the postgraduate thesis can be explained by the inspiration from the thesis studied previously in that field. Eskici and Cayak [23] interprets this situation as "In Turkey, researchers conduct similar research by changing the sample or population of previously conducted research, rather than focusing on new and unique themes." When examining the years in which thesis were done, it is seen that the most postgraduate studies on special education teachers were carried out in 2019, and the least was in 2000, 2001, 2006, 2011 and 2012. When the distribution of postgraduate thesis on special education teachers according to universities is examined, it is observed that they are mostly done in Necmettin Erbakan University and Marmara University. In the examination of postgraduate thesis on special education teachers from the advisor's point of view, it is seen that the faculty members with the title of Assist. Prof. Dr. has advised the most while the faculty members with the title of Dr. has advised the least to the postgraduate thesis in question.
In the examination of 83 postgraduate thesis on special education teachers according to their levels; it is seen that these thesis are mainly studied at master's level and doctoral dissertations are studied less than master's thesis. This situation is also encountered in many studies conducted to examine the levels of master's thesis and doctoral dissertations [11], [13], [23], [24]. It can be said that the acceptance conditions of the doctorate level education is more difficult than the master's education, due to the factors related to the time and opportunity of doctoral education [25], Besides, it can also be stated that this factor plays a role in the fact that doctoral thesis are made less than master thesis.

CONCLUSION
Considering the research methods and models used in the postgraduate thesis on special education teachers, it is observed that the quantitative research method and the correlational survey model was used the most. It can be said that the frequent use of quantitative research method may be the preference of the researcher and the correlational survey model, which is one of the sub-models of the quantitative research model used, may have been used accordingly. It has been determined that single-subject research methods are the least used method in postgraduate thesis on special education teachers. We can say that this may be since single-subject studies are generally a method for practice-oriented studies and that studies related to special education teachers are generally carried out in postgraduate studies on special education teachers.
When the references sections of postgraduate thesis on special education teachers is examined, we see that domestic resources constitute the majority of the resources used in master's and doctoral level thesis. It has been observed that there is no significant difference in the use of domestic and foreign sources in master's thesis and doctoral dissertations, and that domestic sources are used more in master's thesis and doctoral dissertations in general.
According to the results of the research, as recommendations for advanced research, such research should frequently be carried out over certain periods, since such research will give researchers a preliminary idea when determining the original thesis or research topic. Regarding the methods of postgraduate studies on special education teachers; More studies can be done using the single-subject research method. In thesis, the

BIOGRAPHIES OF AUTHORS
Assist. Prof. Dr. Cahit Nuri is a faculty member and head of the Department of Special Education, Cyprus International University. His research on Attention Deficit Hyperactivity Disorder, Autism Spectrum Disorder, Family Education, the sexuality and sexual education of children with special needs. His ORCID iD is https://orcid.org/0000-0003-0805-1972.
Selçuk Özer is a research assistant in the special education department at Cyprus International University. His research on special education, family education and quality of life of special education teachers. His ORCID iD is https://orcid.org/0000-0002-9521-2262.
Merve Parlayan is a research assistant in the special education department at Cyprus International University. Her research on special education, technology in special education and families of children with special needs. Her ORCID iD is https://orcid.org/0000-0001-9472-3661.