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

Psychology teaches us at every step that though two types of activity can have the same external manifestation, whether in origin or essence, their nature may differ most profoundly.

Childhood is a complex dialectical process characterized by periodicity, unevenness in the development of different functions, metamorphosis or qualitative transformation of one form into another, intertwining of external and internal factors, and adaptive processes which overcome impediments that the child encounters.

By giving our students practice in talking with others, we give them frames for thinking on their own.

What a child can do today with assistance, she will be able to do by herself tomorrow.

Writing should be meaningful for children, Y an intrinsic need should be aroused in them, and Y writing should be incorporated into a task that is necessary and relevant.

What children can do with the assistance of others might be in some sense even more indicative of their mental development than what they can do alone