In the current debate on pedagogical content knowledge (PCK), the term is used to refer to the context-specific knowledge that teachers activate when reflecting on practice. Against the background of this debate, we conducted an empirical study and sought to answer the question of which knowledge experts and novices activated in assessing a…

Despite its familiarity and the fact that it becomes a formal area of study in early upper primary grades, optics remains a cognitive challenge for young as well as advanced learners, not only because much of it is counter-intuitive but also because its conceptual comprehension involves negotiating the vocabulary and graphical symbolism involved…

Discusses how an individual's visual system processes cues to motion in depth. A theoretical model of the operations of the visual system that underlie the perception of motion in depth is included. (HM)

Organizes a reading of the conceptual change literature that brings into view a collection of design specifications for a conceptual change apparatus. Analyzes one such apparatus in the particulars of a science education demonstration program produced by the Harvard-Smithsonian Private Universe Project. (Contains 114 references.) (Author/WRM)