This article is a follow-up to my paper published in 2010 (Hume, 2010). In that paper I reported on the use of Content Representations (CoRes) in a chemistry education course to give student teachers insights into the professional knowledge of experienced practitioners: notably their pedagogical content knowledge (PCK), which is “… [the] understanding of how particular topics, problems, or issues are organised, represented, and adapted to the diverse interests and abilities of learning, and presented for instruction” (Shulman, 1987, p. 8). introduced by Shulman (1987) as an academic construct to describe a tacit category of teachers’ professional knowledge base, the exact nature of PCK has been extensively explored and debated. From this debate some agreement has emerged about the components that comprise a teacher’s PCK. This has been identified by Magnusson et al. (1999) as a teacher’s:
• orientations towards science teaching (since teachers’ knowledge and beliefs related to their teaching goals and approaches will influence their classroom practice);
• knowledge of curriculum;
• knowledge of assessment (since what is to be assessed, how and why also influences a teacher’s practice);
• knowledge of students’ understanding of science;
• knowledge of instructional strategies
