In this chapter, the authors apply principles and techniques from the experimental psychology of learning. They assume the behavior of the child is a function of his environment and believe that the person who has the responsibility for the child's environment is the appropriate change agent. The authors utilize the techniques and continue to develop include having educational group meetings with parents, consulting with individual pairs of parents, and structuring a more controlled laboratory-like environment within the home. They deal with the parents of children who are labeled schizophrenic, autistic, brain damaged, or retarded. The purposes of the group are to teach general principles of learning to the parents and to enable them to perform a functional analysis of behavior. There the consultant helped the parents establish two controlled environments: one for about an hour each afternoon with the mother as experimenter, the other for about an hour each evening with the father as experimenter.