The goal of the project is to elaborate an evidence-based framework and practical solutions for effective professional development of adults, including teachers, and the transfer of its results into practice, offering tools for assessing the impact of professional development on practice in Latvia. Implementing a design-based research approach, it is intended to carry out a systemic study of the transfer of professional development of adults, including teachers, into practice, its main obstacles and tools for measuring effectiveness, analysing theoretical knowledge and international experience in coherence of the context and needs of Latvia. The impact of the results of current professional development of adults, including teachers, on practice in Latvia will be analysed, considering the context of existing policy priorities and ongoing reforms. An evidence-based framework for effective professional development of adults and for the transfer of its results into practice will be developed, offering validated practical solutions for assessing the effectiveness of the professional development in organisational and system levels. The results of the research will be presented in at least 5 international scientific conferences. It is envisaged that within the project 3 articles will be submitted or accepted for publication and 3 articles will be published in WoS or Scopus indexed journals/proceedings. It is planned that by the end of the project, 2 Master\'s theses will be defended.