Cognitive Development: The Child's Acquisition of Diagonality is an empirical and rational enquiry into the child's development of a conceptual system relating to the concept of the diagonal during the age range three to six years. A detailed examination will be made of why a young child has difficulty with such a problem, and what occurs during development that removes this difficulty.
In the context of these empirical arguments, the book considers such theoretical questions as the nature of intellectual skills and conceptual or symbolic knowledge, as well as the role of experience and instruction in their development. The study concludes with a description of the child's reconstruction of the diagonal in terms of what at least poses as a general model of perceptual and intellectual development, and accounts for, among other things, man's increasing ability to apprehend and theorize about the motion of the stars. It shows that it is the elaboration of the child's perceptual knowledge in the context of his performatory attempts in such cultural media as language and geometry that accounts for his ability to copy a diagonal in particular and his intellectual development in general.

ForewordPreface1. Introduction Text2. Conceptualizing Conceptualizing: The Diagonal as an Interesting Problem Perceptual Space Representational Space Concepts and Conceptual Space Visual Representation3. The Nature of the Difficulty Problem Difficulty Comparison I Problem Difficulty Comparisons II General Discussion and Conclusions4. The Effects of Instruction Method Results and Discussion Conclusion5. The Change in the Mind of the Child Perception Performance Conceptualization6. Instruction Revisited: Perceptual, Motor, and Linguistic Factors in Cognitive Development Part I Perceptual and Verbal Training and the Acquisition of Diagonality Method Results Discussion and Conclusion Part II Perceptual-Motor and Verbal Training in the Acquisition of Diagonality Phase I Phase II Summary and Conclusion Addendum A Montessori Approach to the Acquisition of Diagonality7. Personal a n d Cultural Experience in Conceptual Development: The Acquisition of t he Diagonal in East Africa Experimental Design Results and Discussion Conclusion8. Looking, Seeing, and Knowing-Eye Movement Studies Method Results Discussion Conclusions9. The Effects of a n Educational Toy on Intellectual Development Educational Toy I Educational Toy II Educational Toy III10. Conclusions: Some Aspects of a Theory of Cognitive Development Perception Language: Perceptual and Semantic Structure of the Orientation of Line Perceiving and Performing Intelligence-Skill in a Medium Instruction SummaryReferencesAuthor IndexSubject Index