The zone of proximal development (sometimes abbreviated ZPD), is the difference between what a learner can do without help and what he or she can do with help. It is a concept developed by Soviet psychologist and social constructivist Lev Vygotsky (1896 - 1934). Vygotsky stated that a child follows an adult's example and gradually develops the ability to do certain tasks without help or assistance. Vygotsky's often-quoted definition of zone of proximal development presents it as "the distance between the actual developmental level as determined by independent problem solving and the level of potential development as determined through problem solving under adult guidance, or in collaboration with more capable peers."
Vygotsky among other educational professionals believes the role of education to be to provide children with experiences which are in their ZPD, thereby encouraging and advancing their individual learning.
The concept of ZPD has been expanded, modified, and changed into new concepts since Vygotsky's original conception.
The concept of scaffolding is closely related to the ZPD, although Vygotsky himself never mentioned the term; instead, scaffolding was developed by other sociocultural theorists applying Vygotsky's ZPD to educational contexts. Scaffolding is a process through which a teacher or more competent peer gives aid to the student in her/his ZPD as necessary, and tapers off this aid as it becomes unnecessary, much as a scaffold is removed from a building during construction. According to education expert Nancy Balaban, "Scaffolding refers to the way the adult guides the child's learning via focused questions and positive interactions." This concept has been further developed by Ann Brown, among others. Several instructional programs were developed on the basis of the notion of ZPD interpreted this way, including reciprocal teaching and dynamic assessment.