The development of spelling knowledge and its role in reading acquisition and reading disability.

In contrast to the hypothesis that dyslexics possess phonological deficits that are neurological in origin, I suggest that the source of the deficit is primarily experiential--that dyslexics exhibit phonological deficits because they have not learned to read and spell in a way that develops their spelling knowledge so that it penetrates and comes to symbolize their phonological knowledge. Evidence from normal reading and spelling development as well as from comparisons of dyslexic and nondyslexic readers is offered to support this thesis.