This paper proposes a model-based notion of "submicro representations of chemical reactions". Based on three structural models of matter (the simple particle model, the atomic model and the free electron model of metals), we suggest there are two major models of reaction in school chemistry curricula: (a) reactions that are simple…

This study explored the relationship between teachers' content knowledge and their pedagogical skills, and reports on that relationship in the teaching of Assembly Drawing (AD) in a South African context. Given that Engineering Graphics Design (EGD) learners perform poorly in the AD section of the matriculation examination, we need to understand…

Visualizing the chemical structure and dynamics of particles has been challenging for many students; therefore, various visualizations and tools have been used in chemistry education. For science educators, it has been important to understand how students visualize and represent particular phenomena--i.e., their mental models-- to design more…

This paper is based on a study which explored the conceptual understanding of Grade 11 mathematics learners of graphical functional relationships, in particular their understanding of the Cartesian plane, notation, symbols and graphical terminology. The National Curriculum Statement (NCS) for Grades 10-12 in mathematics stipulates functional…