Abstract
The system of supplementary education faces the problem of teacher quality. Addressing this issue may be linked to the effectiveness of professional development courses. This effectiveness is determined by the quality of training that stimulates nonlinear and sustainable professional growth among teachers. This article presents the results of an analysis of teachers’ engagement in professional development courses, with the aim of identifying its impact on the actualization of their professional growth. To achieve this aim, the study employed methods of analysis and synthesis, questionnaire surveys, and observation. The research findings are related to the clarification of internal and external motives, as well as factors influencing teacher’s engagement in developmental learning within professional development courses. They also concern the course environment that supports the long-term effect of these motives and factors, as well as the personalization of learning for updating the content of professional development courses. The significance of the results lies in their relevance to the design and redesign of educational programs for professional development courses and to the organization of support for teacher’s professional growth in the workplace. Thus, the findings have practical value for teachers and administrators of supplementary education organizations, developers of educational programs, specialists in the professional development system, as well as analysts and experts in the field of education.