“…Two domains of professional knowledge, content knowledge and pedagogical content knowledge (Section 3.3.3), are important goals of the Foundation's professional development programme because it is assumed that pedagogical content knowledge is a prerequisite for designing and implementing competence-enhancing learning opportunities (Baumert et al, 2010;Carlisle, Kelcey, Rowan, & Phelps, 2011;Hill, Rowan, & Loewenberg Ball, 2005;Sadler, Sonnert, Coyle, CookSmith, & Miller, 2013), and that content knowledge is, in turn, a prerequisite for developing pedagogical content knowledge . With regard to content knowledge, we follow the educational concept of scientific literacy, and differentiate at the level of the pedagogical staff at after-school centres between knowledge of science (Section 3.3.1) and knowledge about science (Section 3.3.2).…”