Masters Degree Thesis, August 2002

The current study tests the phonemic core deficit hypothesis, which is the idea that children with dyslexia experience difficulty in the identification of the phonemes in spoken words. Studies of spelling errors have supported this hypothesis with findings that the most frequent errors children make are substitutions of vowels and consonants (Sawyer, Wade, & Kim, 1999). However, Bracy (2000) found that when spelling long vowels the errors that children make are predominantly orthographic, not phonological in nature. In the current study a frequency analysis of spelling errors by children with dyslexia was conducted. Bracy's findings for long vowels were replicated - children had the most trouble with orthography, followed by letter name spellings. However, short vowels were different. Children with dyslexia had a difficult time identifying short vowels in words that they spell - their most frequent error type was a neighboring phoneme substitution, such as bat for bet. Within short vowels, children did experience difficulty with orthography, but this was a distant second. These findings support Stanovich's (1988) phonemic core deficit hypothesis as an explanation of the signs of dyslexia