Spelling deficits in dyslexia: evaluation of an orthographic spelling training.

Orthographic spelling is a major difficulty in German-speaking children with dyslexia. The aim of the present study was to evaluate the effectiveness of an orthographic spelling training in spelling-disabled students (grade 5 and 6). In study 1, ten children (treatment group) received 15 individually administered weekly intervention sessions (60 min each). A control group (n = 4) did not receive any intervention. In study 2, orthographic spelling training was provided to a larger sample consisting of a treatment group (n = 13) and a delayed treatment control group (n = 14). The main criterion of spelling improvement was analyzed using an integrated dataset from both studies. Repeated-measures analysis of variance revealed that gains in spelling were significantly greater in the treatment group than in the control group. Statistical analyses also showed significant improvements in reading (study 1) and in a measure of participants' knowledge of orthographic spelling rules (study 2). The findings indicate that an orthographic spelling training enhances reading and spelling ability as well as orthographic knowledge in spelling-disabled children learning to spell a transparent language like German.