The focus of this collaborative research project of King's College London, and the Weizmann Institute, Israel is on investigating the ways in which teachers can demonstrate accomplished teaching in a specific domain of science and on the teacher learning that is generated through continuing professional development (CPD) programmes that lead towards such practice. The interest lies in what processes and inputs are required to help secondary-school science teachers develop expertise in a specific aspect of science teaching. It focuses on the design of the CPD programmes and examines the importance of an evidence-based approach through portfolio-construction in which professional dialogue paves the way for teacher learning. The set of papers highlights the need to set professional challenges while tailoring CPD to teachers' needs to create an environment in which teachers can advance and transform their practice. The cross-culture perspective adds to the richness of the development and enables the researchers to examine which aspects are fundamental to the design by considering similarities and differences between the domains.