This study investigated the psychometric properties of the Early Numeracy Screener. The Early Numeracy Screener is a teacher-administered, paper-and-pencil test measuring counting skills, numerical relational skills, and basic arithmetic skills. Three hundred and sixty-six first graders took the Early Numeracy Screener at the beginning of the…

This article presents part of a research project where the aim is to investigate six- to seven-year-old children's language use in storytelling. The children's oral texts are based on the picture book "Frog, Where Are You?" The book consists of a series of episodes that more or less directly point to the plot structure. However, it also…

The visual working memory forms the basis for cognitive processes in learning, and it is therefore of interest to gain greater insight into gender and age differences in visual working memory among pupils. In this study, we wanted to see if there are differences between children in first, third, fifth, seventh and ninth grade in Norwegian schools…

Modern behavior-genetic studies of twins in the United States, Australia, Scandinavia, and the United Kingdom show that genes account for most of the variance in children's reading ability by the end of the 1st year of formal reading instruction. Strong genetic influence continues across the grades, though the relevant genes vary for reading words…

Two ways of measuring change are presented and compared: A conventional "change score", defined as the difference between scores before and after an interim period, and a process-oriented approach focusing on detailed analysis of conceptually defined response patterns. The validity of the two approaches was investigated. Vocabulary…

In this paper, we estimate the effect of pupil's relative age within the first grade of primary school on mathematics and reading test scores at age 15. The main objective is to evaluate the long-term causal effect of relative age in the first grades of primary school on pupil's test in 16 different countries. We use the national rule for…

Genetic and environmental relations between vocabulary and reading skills were explored longitudinally from preschool through Grades 2 and 4. At preschool there were strong shared-environment and weak genetic influences on both vocabulary and print knowledge but substantial differences in their source. Separation of etiology for vocabulary and…