Robin van Rijthoven

96 Chapter 4 It can be concluded that in general, orthographic spelling is more difficult than phonological spelling, but that children with dyslexia differ far more from typically developing children in the proportion of phonological errors compared to the difference in the proportion of morphological and orthographic errors. This is in line with their phonological deficit and implies that children with dyslexia need an intervention that stimulates both phonological and orthographic spelling development, but especially phonological errors since the differences with typically developing children are biggest. This study contributes to the existing literature by demonstrating that children with dyslexia with strong semantic representations, appear to make fewer phonological, morphological, and orthographic spelling errors, compared to children with dyslexia with less developed semantic representations and children with dyslexia with better developed verbal working memory make fewer morphological errors compared to children with dyslexia with better developed verbal working memory. Our study shows that a phonics through spelling intervention benefits both phonological and orthographic spelling development quite evenly among children with dyslexia but that there is a positive additional effect of semantic abilities on the progress during the intervention as well. Promising effects of integrating semantic abilities in spelling interventions were found before (Ouellette, 2010; Ouellette & Fraser, 2009). Therefore, it is recommended to stimulate the semantic development of children that are at risk for dyslexia at an early stage and throughout their school carrier in order to help thembuild strong semantic networks to compensate in their spelling development. Furthermore, semantic abilities could be stimulated during interventions as well in order to stimulate spelling development even further.