Most educators are familiar with Lev Vygotsky's concept of the zone of proximal development, yet the bulk of Vygotsky's pioneering theory of cognitive development largely remains unknown. This unique volume provides a systematic, authoritative overview of Vygotsky's work and its implications for educational research and practice. Major topics include how children develop higher-order thinking; the influences on cognitive development of teacher-student interactions, the family, and culture; and critical and stable periods in development from infancy through adolescence. Key concepts and research methods are explained in detail, and classroom examples and instructional suggestions are provided.