In this study we investigated variations in parental tutoring of children on the basis of Vygotsky's (1978) theorizing and the concept of parental scaffolding of children's learning. Twenty-four couples and their 3-year-old children participated. Mothers and fathers worked separately with the child on three difficult tasks: a block construction task, a matrix classification task, and a story retelling task. Parental interventions were classified by level of support and were used to define the region of sensitivity to instruction, following the work of Wood (1980). Independent observers rated each parent separately on authoritative/uninvolved and authoritarian/permissive styles, following Baumrind's (1967, 1973) typology. Both mothers and fathers adjusted their support of the child as predicted. Later portions of the tutoring interactions demonstrated more fine tuning of interventions by parents than earlier portions. However, authoritative mothers and fathers were generally more likely than nonauthoritative parents to focus interventions in the region of sensitivity across tasks and to shift their interventions contingent on child success or failure. These patterns were also associated with more dyadic success on task as predicted. We discuss relations between these two levels of parenting style. Recently a good deal of attention has been directed to the work of the Russian developmentalist Vygotsky (e.g., 1978), whose theoretical writings focused explicitly on the role of adult-child interaction in the socialization of early cognitive development. Vygotsky argued that all higher planning and organizing functions in development appear twice, initially on the interpersonal plane of social interaction and subsequently on the intrapersonal plane of individual cognitive functioning, following a process of gradual internalization. Most important in terms of the study reported here, Vygotsky's theory entails a specific model for the organization of adult-child teaching interactions (e.g., Vygotsky, 1978; Wertsch, McNamee, McLane, & Budwig, 1980). Initially, complex tasks must be accomplished by such a problem-solving dyad, with the adult assuming the directive and organizing functions. The child's role may be simply to enact the specific behaviors assigned to him or her by the adult tutor. Gradually, however, as the child becomes more knowledgeable and skilled, he or she takes over more and more of the goal-oriented, planning aspects of the task from the adult. Thus, Vygotsky suggested that learning by