Akira, a 4-year-old boy, wanders into a classroom of 3-year-olds, observing the younger children. He goes over to Masaharu who is having a problem making a piece fit on a puzzle and offers him help. Masaharu succeeds and his mentor applauds his efforts. This interaction shows an older child supporting a younger child through scaffolding. Using scaffolding, a more mature or more competent peer or an adult might offer hints--without actually providing the solution--to help a child progress in a task. The interaction between Akira and Masaharu is indicative of how children in many Japanese preschools help each other. In Japanese preschools that subscribe to group-oriented approaches that strongly encourage children's social interactions, scaffolding between children, as well as between teachers and children, is evident everywhere. When scaffolding a child's learning, it is important to vary the degree of assistance, according to the learner's needs. Effective scaffolding depends on teachers' ability to engage children's interest and on their asking open-ended questions that support children's thinking and reflection. Questions should acknowledge children's existing knowledge and experiences, and guide their thinking to a higher level in their zone of proximal development. In scaffolding, children's active participation is important. Additionally, it is important for teachers to support children's scaffolding of other children's learning by offering them opportunities to do so and by encouraging younger and older children's interactions.