Twelve culturally disadvantaged 4-year-olds of borderline normal intelligence were subjects of this study. Its primary purpose was to test further the cognitive learning theory previously developed, as well as the reinforcement system, the facilities, and the experimental-longitudinal methods of research. The study did not include a control group…

A group of 161 kindergarten and first grade children were instructed in mathematics using exercises in linear measurement to increase understanding of unit-quantity relations. A comparison group made up from two adjacent and comparable middle-class schools was taught mathematics without intervention into the mathematics content. Treatment and…