To be presented at the 17th Annual Meeting of the Society for the Scientific Study of Reading, Berlin, Germany, 7–10 July 2010

Purpose: To propose a classification system for spelling errors and determine the most common spelling difficulties of Greek children without and with dyslexia.
Method: Spelling skills of 566 children from the general population and 61 children with dyslexia, in Grades 3–4 and 7–8, were assessed with a dictated common word list and an age-appropriate passage. Spelling errors were classified into broad categories, including phonological (graphophonemic mappings), morphological (inflectional suffixes), etymological (word stems), stress assignment (diacritic), and punctuation. Errors were further classified into specific subcategories. Chronological-age and reading-age control groups were formed by selected nondyslexic children.
Results: Relative proportions for a total of 15066 errors were derived by calculating the opportunities for each error type. Nondyslexic children of both age groups made primarily morphological and stress errors, followed by etymological errors. Phonological and punctuation errors were negligible. Most frequent specific errors were in derivational affixes, stress diacritics, inflectional suffixes, and vowel historical spellings. Older children made fewer errors, showing greater improvement in morphological spelling. Dyslexic children differed from nondyslexic in making more errors of the same types, in comparable relative proportions. Older dyslexic children differed more from nondyslexic children in error counts but not in error types, and made more errors than reading-matched younger children.
Conclusions: Most spelling errors of both dyslexic and nondyslexic children indicate persistent difficulty with internalizing regularities of the Greek orthographic lexicon, including derivational, inflectional, and word (stem) families. This difficulty is greater for children with dyslexia. No qualitative differences emerged in dyslexic spelling patterns.