This study was a mixed quantitative-qualitative research to evaluate the efficacy of a designed student-centred instructional (DSCI) program for teaching about acids and bases. The teaching innovation was designed based on constructivist, hands-on inquiry and context-based approaches and implemented in seven 45-min lessons with a class of 36 grade…

Reports in detail on a year-long case study of multiple-model use at grade 11. Suggests that students who socially negotiated the shared and unshared attributes of common analogical models for atoms, molecules, and chemical bonds used these models more consistently in their explanations. (Author/CCM)

Describes a conceptual typology of models to help teachers select models appropriate to the cognitive ability of their students. Presents an example of how the systematic presentation of analogical models enhanced an 11th-grade chemistry student's understanding of atoms and molecules. Makes recommendations for teachers. Contains 28 references.…

Chemistry is commonly portrayed at three different levels of representation--macroscopic, submicroscopic and symbolic--that combine to enrich the explanations of chemical concepts. In this article, we examine the use of submicroscopic and symbolic representations in chemical explanations and ascertain how they provide meaning. Of specific interest…