Key points are not available for this paper at this time.
Contents: Foreword. Preface. Introduction. Conceptualizing Conceptualizing: The Diagonal as an Interesting Problem. The Nature of the Difficulty. The Effects of Instruction. The Change in the Mind of the Child. Instruction Revisited: Perceptual, Motor, and Linguistic Factors in Cognitive Development. Personal and Cultural Experiences in Conceptual Development: The Acquisition of the Diagonal in East Africa. Looking, Seeing, and Knowing -- Eye Movement Studies. The Effects of an Educational Toy on Intellectual Development. Conclusions: Some Aspects of a Theory of Cognitive Development.
Sher et al. (Sat,) studied this question.