摘要：As one of the crucial elements of education system, teachers’ professional development is important to equip them with the education to compensate the needs of modern life. The major aim of this research is to determine the views of school principals and science teachers on the concept of professional development, and identify factors which affect science teachers’ professional development. Both qualitative (semi-structured interview) and quantitative (survey) research methods were used in the research. The sample consisted of school principals and science teachers who were working in Nevşehir province and its districts. 6 school principals and 6 science teachers were interviewed in-depthly. In addition, data from 109 science teachers were also collected through questionnaires. The data obtained through interviews were analyzed by descriptive analysis. Simple correlation technique and percentage distributions were used to analyze the questionnaires. The research findings show that in general, the teaching profession is being perceived as a profession which starts with pre-service training and continues with in-service training; therefore, it is an ongoing process. It has also been discovered that in this process, "personal and external factors" affect science teachers' professional development. Thus, teachers’ professional development should be supported in line with these factors.
