The 17-month (1967-1968) study summarized in this report concerned experimental analysis of the verbal behavior of disadvantaged preschool children (an interracial group of 28, ranging in age from 30 months to 42 months). Research was conducted in the verbal behavior laboratory at the University of Rochester and in a remodeled private home in a low-income area of the city. Teaching strategy consisted of analyzing the behavioral targets, establishing requisite antecedent behavior (RAB) under tightly controlled teaching conditions, integrating these behaviors with other activities in the nursery school, and finally establishing more complex RABs. The chief result of the research is a series of programs and procedures which proved successful in modifying the children's behavior. Included are tables showing results of tests and of management and efficiency measures; discussion of teaching tactics, apparatus, and materials; a program outline; descriptions of games; an appendix; and a list of related publications. (JM)