ABSTRACT
Sfard ended her comparison by showing that am and p m complement each other, and together offer what might be called a three-dimensional (3-D) view of development. Resnick ( 1994) considered not the a m as such but the view that biological maturation prepares the learner to acquire certain concepts at certain times. This, she argued, should be integrated with p m ideas. No doubt others will join Sfard, Resnick, and Snow in calls for the synthesis of these positions. After introducing aspects of the pm view, this chapter begins to consider in some detail how aptitude theory can incorporate ideas from the p m school. These ideas are revisited and developed in chapter 8.
