It would have been desirable for the two communities to have differed only in respect to the variable being investigated: the degree of structure in teaching method. The structured schools were in an industrial city, with three family tenement houses typical of the residential areas, but with one rather sizable section of middle-class homes. The unstructured schools were in a large suburban community, predominantly middle -- to upper-middle class, but fringed by an industrial area. In order to equate the samples on socioeconomic status, we chose schools in both cities on the basis of socioeconomic status of the neighborhoods. School principals and guidance workers made ratings of the various neighborhoods and the research team made independent observations of houses and dwelling areas. An objective scale was developed for rating school neighborhoods from these data. Equal proportions of children in each city were drawn from upper-lower and lower-middle class neighborhoods.

Individual differences in maturation and the development of readiness for learning to read indicate that not until the third grade have most children had ample opportunity to demonstrate their capacity for school achievement. Therefore, third grade children were chosen as subjects for this study.

For purposes of sample selection only (individual tests were given later) we obtained group test scores of reading achievement and intelligence from school records of the entire third grade population in each school system. The subjects for this study were randomly selected from stratified areas of the distribution, one-third as underachievers, one-third medium, and one-third over-achievers. Children whose reading scores were at least one standard deviation below the regression line of each total third grade school population were considered under-achievers for the purposes of sample selection. Over-achievers were at least one standard deviation above the regression line in their school system. The final sample was not significantly different from a normal distribution in regard to reading achievement or intelligence test scores. Twenty-four classrooms in twelve unstructured schools furnished 156 cases, 87 boys and 69 girls. Eight classrooms in three structured schools furnished 72 cases, 36 boys and 36 girls. Administrative restrictions necessitated the smaller sample size in the structured schools.