The major purpose of this research project, conducted as a part of the Huntsville-Madison County Education Improvement Program, was to generate basic data in order to determine the effect of a preschool intervention program on a population of socioeconomically disadvantaged children. Specifically, cognitive, demographic, learning, material, method, perceptual, and teacher characteristic data were considered to be of prime importance. The first generalization that may be drawn from this extensive research is that such preschool programs may and frequently do have positive effects on the cognitive functioning of economically deprived children. However, there is no single program, curriculum, or approach that appears to provide outstanding advantages. tTeacher personality factors, organizational skills, and teaching ability appeared to play the decisive role in children's performance. Observations made of classroom procedures and of reactions to teacher in-service meetings tended to point to morale and commitment to the programs as highly influential factors influencing teachers' reactions to the program and their attitudes toward the children. This may be of special importance in such programs as this because of their experimental nature. (Author/JM)