Answer: Scaffolding
Explanation:
Scaffolding is the mechanism in which instructions and guidance is provided to the student so that he/she can learn and then student performs the activity on their own .Help is provided to students in form of hints or instruction whenever they require.
According to the question, Walter's mother is using scaffolding method for making Walter learn about tying shoelaces. His mother guided and helped him at first and then made Walter do it himself .She only helped when he needed.