Differentiation hypotheses concern changes in the structural organization of cognitive abilities that depend on the level of general intelligence (ability differentiation) or age (developmental differentiation). Part 1 of this article presents a review of the literature on ability and developmental differentiation effects in children, revealing…

The purpose of the study was to examine if there was a significant difference between first-grade English Learners (EL) who constitute a majority (greater than 50%) of the English language mainstream classroom (homogeneous grouping) and first-grade EL who constitute a minority (less than 50%) of the English language mainstream classrooms…

In connection with the growing complexity and intensiveness of school instruction, special urgency attaches to the task of ensuring that the organization of the educational process at different levels of school is in keeping with the developmental stages of psychophysiological and social development. A number of researchers have emphasized the…

The achievement gap in mathematics between African American and Caucasian students has been observed for several decades, though previous research has been unable to fully explain why the gap exists. Using a sample of 56 kindergarten and first grade students, this study examined the role that cognitive developmental level plays in the achievement…