Vygotsky couples the mechanism to a setting. The Zone of Proximal Development (ZPD) is that sweet domain of tasks not yet performable alone but readily accomplished with assistance. Within it, a More Knowledgeable Other (MKO) provides scaffolds—verbal frames, prompts, decompositions of action—that the learner initially leans upon and eventually incorporates. The process is not merely additive; it reorganizes. New mediational means alter the very form of thought.