PREFACE TO THE SPECIAL SECTION
This Invited Special Section is the second and last of the series Contributions of Educational Research to the Practice of Chemistry Education. It contains three contributions by Robert Bucat, Peter G. Mahaffy, and Avi Hofstein. In their position papers, Bucat and Mahaffy deal with the connection of the content of chemistry with the learner. Bucat calls for the use of pedagogical content knowledge, while Mahaffy proposes the metaphor of ‘tetrahedral chemistry education’. Hofstein, on the other hand, reviews educational research on the role of laboratory in chemistry education.