The commognitive theory framework: From theory to implementation

This chapter describes several projects deriving from Sfard's Commognitive Theory. After providing a brief outline of its major tenets and concepts, we describe implications of this theoretical framework in four areas of practice: Preservice teacher preparation, in-service professional development, introduction of math ematical texts to high school students and diagnosis of mathematical learning difficulties. We end with a discussion of the affordances and challenges of linking the Commognitive Theory with practice.