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…

In contrast to classical phonological span tasks, which require verbal recall, those used in self-reliant, group-administrable working memory measurement contain a visuospatial response format. As a consequence, these tasks involve recoding, executive, and visual search requirements in addition to encoding and storage processes. To examine…

Children's estimation skills on a bounded and unbounded number line task were assessed in the light of their familiarity with numbers. Kindergartners, first graders, and second graders (N = 120) estimated the position of numbers on a 1--100 number line, marked with either two reference points (i.e., 1 and 10: unbounded condition) or three…

Mathematical competencies are important not only for academic achievement at school but also for professional success later in life. Although we know a lot about the impact of "Home Literacy Environment" on the development of early linguistic competencies, research on "Home Numeracy Environment" (HNE) and the assessment of its…

In the course of elementary school, children start to develop an academic self-concept reflecting their motivation, thoughts, and feelings about a specific domain. For the domain of mathematics, gender differences can emerge which are characterized by a less pronounced math self-concept for girls. However, studies are rather sparse regarding the…

In a cross-sectional study, we examined the relationship between the quality of lexical representations and text comprehension skill in German primary school children (Grades 1-4). We measured the efficiency and accuracy of orthographical, phonological, and meaning representations by means of computerized tests. Text comprehension skill was…