Developmental psychologist Lev Vygotsky defined what the person or a student can do — or the problems they can solve — as three different stages:
- What a student can do on their own, working independently or without anyone’s help.
- What the student can do with the help of someone.
- What it is beyond the student’s reach even if helped by someone else.
He called the second stage the Zone of Proximal Development (ZPD) which had, as said, two limits: the lower limit, which was set by the maximum level of independent performance, and the upper limit, the maximum level of additional responsibility the student can accept with the assistance of an able instructor. But "Vygotsky believed that learning shouldn’t follow development, but rather should lead it. A student should constantly be reaching slightly beyond their capabilities rather than working within them" (Jo Turner-Attwell, 2009).
This reaching beyond one’s capabilities can be pictured as the student entering their Zone of Proximal Development. And this exploration beyond one’s capabilities is not to be made alone, but with an instructor to help in the way. Vygotsky called this instructor the More Knowledgeable Other (MKO), the role of which is to help the student throughout their ZPD by scaffolding the path they have to follow to learn how to solve new problems.