How can we help infants, toddlers and preschoolers get ready for the challenges of grade school and make satisfactory progress during the early years of formal schooling? Although interest in this question dates back more than 30 years to the inception of compensatory early childhood programs (e.g. Head Start), its importance has grown in recent years as accumulating evidence has revealed that children’s performance during the primary school years (Kindergarten through Grade 3) has an important bearing on their later success in school and in life.1 Consequently, understanding how young children are best prepared to enter and succeed in grade school has become a priority among parents, educators, legislators and researchers.