To compare the effectiveness of the traditional and the experimental approaches to Head Start classrooms, 68 children and six teachers in San Francisco participated in an educational experiment. The traditional approach emphasizes the children's internal motivation resulting from spontaneous free play and warm, accepting teachers, while the experimental approach emphasizes social learning theory in the form of teacher-directed activities and frequent praise or reinforcement for appropriate behaviors. Each of the six teachers was given a choice of approach. Three chose traditional; three experimental. The classrooms were observed and evaluated for student behavior (Child Behavior Survey Instrument) and teacher behavior. The three teachers in the experimental approach did not carry out their roles as praise-dispensers, thus making the more desirable behavior of the children in the traditional approach classes meaningless for any comparison of the two approaches. The major implication of this research is that actual application of social learning theory requires more than agreement with its principles. Observed intra-approach differences suggest that a study of individual teacher style is needed as well as a recognition that different children thrive in different kinds of classrooms. (MH)