The effects of training of morphological structure on spelling derived words by dyslexic adolescents.

This exploratory study aimed to determine the effects of explicit instruction about morphological structure on the spelling of derived words. A cross-sectional ability level-design was employed in order to determine differences in response to instruction between dyslexic students aged 13 + years and age-matched and spelling level matched control groups. The study was based on the word-pair paradigm (a base and derived word) and combined oral instruction with written materials. The intervention had a substantial impact in enhancing the spelling of derivations by the dyslexic adolescents. Their gains were appropriate for their spelling level, stable two months after the intervention, and generalized to untrained but analogous items in terms of structure and suffixation. Non-dyslexic younger participants matched in terms of spelling level also showed training and generalisation effects of the same size as their dyslexic counterparts, while the age-matched controls did not improve so much because of ceiling effects. It is proposed that morphological awareness constitutes a positive asset for dyslexic adolescents that can be used efficiently to counterbalance their severe phonological deficiencies.