Secondary mathematics teachers' pedagogical content knowledge

Stefan Krauss, Jürgen Baumert and Werner Blum have written an article entitled Secondary mathematics teachers’ pedagogical content knowledge and content knowledge: validation of the COACTIV constructs. The article (which is an Open Access article!) was published online in ZDM last week. This is a very interesting article, which gives a nice contribution to the field of research related to teachers' knowledge. It builds upon the framework of Shulman, and it gives a nice overview of these theories, as well as an overview of some of the other research projects that have been contributing to this field (like the study of Ball, Hill, Schilling et al. in Michigan). Here is the abstract of the article:
Research interest in the professional knowledge of mathematics teachers has grown considerably in recent years. In the COACTIV project, tests of secondary mathematics teachers’ pedagogical content knowledge (PCK) and content knowledge (CK) were developed and implemented in a sample of teachers whose classes participated in the PISA 2003/04 longitudinal assessment in Germany. The present article investigates the validity of the COACTIV constructs of PCK and CK. To this end, the COACTIV tests of PCK and CK were administered to various “contrast populations,” namely, candidate mathematics teachers, mathematics students, teachers of biology and chemistry, and advanced school students. The hypotheses for each population’s performance in the PCK and CK tests were formulated and empirically tested. In addition, the article compares the COACTIV approach with related conceptualizations and findings of two other research groups.