ICTlogy » ICT4D Blog » Personal Learning Environments and the revolution of Vygotsky’s Zone of Proximal Development | Educational Technology in Higher Education | Scoop.it
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.