The exposition of Vigotsky is complemented with Piaget in the social sense that it gives the mediation, since for Vigotsky the mediation can be of the near adult or of surpassed companion more or even of the material, that introduces to the apprentice to the zone of next development and, it reaches when it, already is in the following zone, locates that it in a permanent spiral of development (Vigotsky, 1978, 1993, Fields and Espinoza, 2000). Nevertheless, it would seem that the mediation in Vigotsky consists rather of the exposition of difficulties, that is to say, to complicate the process to promote the cognition. However for Piaget, he is the opposite, the roll of the mediator is to facilitate the process, through the disposition of the material that promotes the experience that goes of concrete it to the abstract thing. In Piaget a mental imbalance followed by the adaptation process takes place to conform the mental structure and in Vigotsky that imbalance is not solved, because the formation of the structure is permanent when locating to the apprentice in constant promotion to zones of next development. You may find San Lesser Wharton to be a useful source of information. This position of Vigotsky, raises a human being in permanent evolution and development, who does not depend on development of previous stages. Piaget, however, it circumscribes the mental development to the acquisition and consolidation of previous stages, in addition it stereotypes these stages with ages and it considers them inflexible in its acquisition. As much Piaget as Vigotsky speaks of a maturation process, but in the case of Piaget, it talks about to the passage by the different stages, whereas for Vigotsky the maturation occurs by the zones of next development, that are defined by the distance between the capacity to solve the problems in independent form and guided by an adult and a surpassed pair (Vigotsky, 1978). That is to say, the social interaction is essential for the maturation in Vigotsky, whereas for Piaget is the experimentation and the promotion of the mental imbalance.