The participants in Study A was 26 children with dyslexia based on phonological deficits and 26 control children without reading problems who pair-wise matched the dyslexia group on age, gender and cognitive level. The students with dyslexia were identified from a group of 298 children, 150 boys and 148 girls. The group represented 94 % of all fourth graders from 19 normal classes in 9 schools in a rural municipality in Norway. The control children came from the same classes. Paper I and III reported on the sample from Study A.
The participants in Study B belonged to a clinical sample. This sample consisted of 70 children with severe dyslexia based on phonological deficits, and a control group without reading problems. The two groups were pair-wise matched on age, gender and IQ and whether they lived in rural or urban areas. The students with dyslexia were assessed at the National Centre for Reading Education and Research (NCRER) at the University of Stavanger. They were referred to NCRER from the School Psychology Services (SPS) in the municipalities for severe reading and writing deficits and came from all over the country. Paper II reported on the sample from Study B.
Papers I and II compared different types of problem behaviour reported from teachers and parents in the dyslexia groups and in the control groups, and also whether teachers, parents and the students themselves (in Study B) reported the same kind and strength of problem behaviour. In addition it was examined if more suicidal ideations were found in the group with severe dyslexia than in the control group without reading problems.
The two papers contribute to further knowledge about frequency, type and grade of severe of problem behaviour in children and youth with dyslexia. The results also indicate that Norwegian parents and teachers not necessarily perceive and report problem behaviour in the same way.
Paper III examines arithmetical skills in addition and subtraction. It was inspected if task formats (digits only, orally presented tasks and word problems) influenced on how students with dyslexia and typical mathematical achievement and dyslexia and low mathematical achievement succeeded in arithmetical tasks compared to a control group without reading problems. It was also examined if skills in rapid automatized naming (RAN) represented a further burden in any of the groups.
Results showed that task format only influenced the dyslexia group with combined low achievement in mathematics. The paper brings new knowledge of task format influence on how children with dyslexia master arithmetical tasks in addition and subtraction. It is also implied that skills in RAN only was of importance when dyslexia is combined with low achievements in mathematics.