The language of science has many words and phrases whose meaning either changes in differing contexts or alters to reflect developments in a given discipline. This book presents the authors theories on using conceptual profiles to make the teaching of context-dependent meanings more effective. Developed over two decades, their theory begins with a recognition of the coexistence in the students discourse of those alternative meanings, even in the case of scientific concepts such as molecule, where the dissonance between the classical and modern views of the same phenomenon is an accepted norm....