Examines ways in which knowledge might be captured, articulated, and portrayed to others. Develops an approach to articulation and portrayal based on what is called the CoRe (Content Representation), which represents the particular content/topic of the science teaching, and PaP-eRs (Pedagogical and Professional experience Repertoire), which illuminate specific aspects of the CoRe and therefore offer insights into pedagogical content knowledge itself. (Author/MM)