Based on the papers presented at the 1996 Symposium of the Jean Piaget Society and highlighting the extent to which Piaget's ideas have served to scaffold contemporary thinking about every aspect of conceptual development, this volume examines the nature of conceptual development, its foundations, and the sources of its novelties. The chapters are: (1) "Piaget's Legacy: Heirs to the House that Jean Built" (Ellin Kofsky Scholnick); (2) "Conceptual Development in the Child and in the Field: A Personal View of the Piagetian Legacy" (Robbie Case); (3) "A New Foundation for Cognitive Development in Infancy: The Birth of the Representational Infant" (Andrew N. Meltzoff and M. Keith Moore); (4) "A Reconsideration of Concepts: On the Compatibility of Psychological Essentialism and Context Sensitivity" (Susan A. Gelman and Gil Diesendruck); (5) "Explanatory Understanding in Conceptual Development" (Frank C. Keil and Kristi L. Lockhart); (6) "The Conceptual Habitat: In What Kind of System Can Concepts Develop?" (David Klahr); (7) "A Systemic Interpretation of Piaget's Theory of Knowledge" (Rolando Garcia); (8) "Locating Development: Locating Developmental Systems" (Susan Oyama); (9) "Developmental Change: Lessons from Microgenesis" (Patricia H. Miller and Thomas R. Coyle); (10) "The Origin of Piaget's Ideas about Genesis and Development" (Jacques Voneche); (11) "Sources of Concepts: A Cultural-Developmental Perspective" (Geoffrey B. Saxe); (12) "Levels and Modes of Representation: Issues for the Theory of Conceptual Change and Development" (Katherine Nelson); and (13) "Sources of Conceptual Change" (Susan Carey). Each chapter contains references. (KB)