The small-scale study presented here was the first test of three instruments in a sample of Icelandic children: IS-FORM, IS-PSEUDO, and the Strengths and Weaknesses of ADHD-symptoms and Normal-behavior (SWAN) rating scale. Participants in this study were children in the 4th grade of a school in Reykjavik (10 girls and 10 boys). Guardians completed SWAN to assess their children's behavior. The researchers measured children's reading fluency for real Icelandic word forms (IS-FORM) and pseudowords (IS-PSEUDO) onsite. Lesferill standardized reading fluency exam scores and both Icelandic language and mathematics scores from the 4th grade Icelandic National Exams (academic achievement) were collected from the Directorate of Education. IS-FORM and IS-PSEUDO showed all signs of being reliable and valid instruments for assessing the reading fluency of 4th grade children (Chronbach's alpha for the IS-FORM 1, IS-FORM 2, and IS-PSEUDO together was .87). SWAN also had excellent reliability in our sample (Cronbach’s alpha of .96). A forced two-factor solution provided a factor structure that aligned well with the ADHD-Inattentive and ADHD-Hyperactive/Impulsive subscales of SWAN. SWAN scores correlated with all reading measures, but not significantly with academic achievement, and the strength of this association got stronger from 2nd to 5th grade. The results suggest that ADHD-related symptoms and behavior hinder children from reaching their full reading fluency potential.This research was funded by The Icelandic Research Fund (Grants No. 174013-051, 195912-053) and the University of Iceland Research Fund.Accepted peer-reviewed chapte
