The aim of this study is to develop more understanding about strategies to support teachers' professional development in curriculum innovations, in which pedagogy and content change simultaneously compared to the conventional curriculum. A pre-existing framework, including strategies for professional development, was adapted, implemented, and evaluated from the perspective of teachers' sense-making in teaching context-based science curricula. This framework guides the design of activities that support teachers' development in three new aspects of teaching context-based science units: setting a context in class, performing a new teaching role, and teaching new content. In a case study, six teachers in secondary education participated in a professional development program based on the adapted framework. A qualitative inner-case analysis was conducted to describe teachers' sense-making during the program, in terms of the categories "assimilation," "accommodation," "toleration," and "distantiation." Results showed that teachers participating in the professional development program successfully assimilated and accommodated all three aspects; however, the process of teachers' sense-making of

This study aims to determine and describe the new domain-specific expertise of experienced chemistry teachers in teaching an innovative context-based unit about macromicro thinking in structure-property relations. The construct of 'teachers' domain-specific expertise' was used to analyse the new repertoire chemistry teachers need to acquire to teach a context-based unit and achieve the intended effects of the curriculum innovation. A phenomenological approach of exploration and verification of teachers' new repertoire resulted in the description of seven themes. These themes were related to the new aspects of the unit: the context-setting, the teacher's role and the new content. In addition, the results show that the theoretical framework of teachers' domain-specific expertise is feasible for the analysis and description of their new repertoire in the domain of teaching a contextbased unit. Further research is necessary to explore the use of the framework from the perspective of teachers' professional development, where affective components in teachers' learning processes play an important role.