major developmental theories, like those of piaget and werner, stress that the interaction of the child with his or her environment is the fundamental basis of development. piaget refers to this as the aliment, or "food for thought." piaget's theory is an active theory, in that assumes the child to be an active being, interacting, exploring, discovering. children need, therefore, to play and learn in environments that are rich in resources, and to explore, test, and learn from feedback on their own actions in a resource-rich environment. the richer the environment, and the more freedom the child has to explore, to make mistakes, and to learn from those mistakes, the more developmentally appropriate is that environment.