P. M. Lewinsohn has theorized that depression is related to the amount of positive reinforcement that an individual receives. Lewinsohn has supported this model in adults by showing that depression is correlated with an increase in unpleasant activities and a decrease in pleasant activities. This study extended Lewinsohn's model by developing…

A study was conducted to identify types of mental operations of 4- and 5-year-olds and to relate them to the child's age and the educational level of the mother. The sample consisted of 423 white English-speaking children of American parentage, evenly divided by sex and as evenly distributed as possible over the 12-month-age range of 4 to 5 years.…

Explores the impact of the social and academic diversity of the class on teachers' perspectives about their schools as workplaces. Data from 370 Israeli secondary teachers indicate that classroom diversity is correlated negatively with average academic ability and positively with class size and discipline problems. (SLD)

Relationships between performance on two preschool administrations of the Metropolitan Readiness Tests (MRT) and Stanford Achievement Test (SAT) scores at age nine were examined for a sample of 732 children. Significant correlations, ranging from .50 to .71, were obtained between readiness scores and SAT scores on reading, spelling and arithmetic.…