Vygotsky introduced the notion of Zone of Proximal Development (ZPD) as a large area of potential development that is created when learners are supported by others. (elearningindustry.com)
In order to meet students where they are and appropriately scaffold a lesson, or differentiate instruction, you have to know the individual and collective zone of proximal development (ZPD) of your learners. (edutopia.org)
Mastery - based learning Formative assessment Collaborative learning Metacognition Scaffolded instruction Zone of proximal development (knewton.com)