Alberto is learning algebra. His teacher provides him with classroom instruction and algebra problems to work on at home. The teacher also solves problems with the class showing the students each step in the process of solving the algebra problem. When concepts are new, the teacher interacts often with Alberto and his classmates, showing them how to perform algebraic operations, giving subtle hints, asking leading questions, and making suggestions. As Alberto becomes more competent in his new skills, his teacher begins to back off, allowing him to work with increasing independence. Alberto's teacher has used the constructivist principle of