This report outlines a method for analyzing the status of stimuli which control deviant child behavior. Hypothetically, an effective family treatment program would not only alter the reinforcing contingencies provided by family members for the deviant behaviors of the problem child, but would also reduce the frequency with which they present these behaviors which signify the availability of reinforcers. The data in this study, extensive samplings of sequential interactions found among family members, were collected in the home of an extremely disruptive boy. The analyses of these data were then used to illustrate shifts in stimulus control produced by a family intervention program; the data showed the parents to be only moderately effective in reducing the rate of deviant child behaviors for their problem child. However, there were changes from baseline through follow-up in the number of social behaviors which served as controlling stimuli for noxious behaviors; and, as treatment progressed, those stimuli which did significantly control deviant behaviors were also presented at lower densities. Presumably, these changes were largely the result of the parents' success in altering behaviors of the younger sister which had provoked deviant responses from the problem child. Findings suggest that analysis of stimulus control may constitute a subtle description of changes in family structure. (Author/SES)