"... the distance between the actual development 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 (1978, p.86)

• (a) An operation that initially represents an external activity is reconstructed and begins to occur internally
• (b) An interpersonal process is transformed into an intrapersonal one.
• (c) The transformation of an interpersonal process into an intrapersonal one is the result of a long series of developmental events.

Lev S. Vygotsky (1978) "Mind in society", Harvard UP, Cambridge
Edited by Michael Cole, Vera John-Steiner, Sylvia Scribner, Ellen Souberman

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