Graduation Year


Document Type




Degree Granting Department

Communication Sciences and Disorders

Major Professor

Sylvia F. Diehl, Ph.D.


Phonology, Orthography, Autism, POMAS, Literacy


Learning to spell requires integration of phonological, orthographic, and morphological knowledge. Historically, spelling development has been characterized by linear stages in which children learn to use these knowledge bases in succession. A more recent view challenges the linearity of this approach and proposes that spelling development from the beginning is characterized by the simultaneous interaction of all three linguistic factors. Minimal research exists that qualitatively investigates the integration of these three factors, especially as noted in derivational morphology. The study's purpose was to investigate spelling accuracy and qualitatively analyze the morphological error patterns of typically developing children, ages 8-15 years, for a future comparison to children with autism spectrum disorders (ASD).

Twenty-nine typically-developing children were age- and gender-matched to children with ASD from a companion study (Wiggins, 2009) to conduct quantitative comparisons. After inclusion measures were administered, the children completed a spelling test that analyzed various morphological aspects of spelling, including homonyms, inflections, and derivations. Results of the quantitative analyses revealed that children in the ASD group made significantly more errors than children in the typically developing group on the spelling test. Nevertheless, performances across the morphological categories tested were similar across groups and followed the pattern described in previous research (Carlisle, 1988, 2000).

Qualitative analysis used a unique coding system, the Phonological, Orthographic, and Morphological Analysis of Spelling (POMAS; Silliman, Bahr, & Peters, 2006), which allowed for analysis by linguistic category (e.g., phonological, orthographic, morphological) and specific error features (e.g., letter-sound correspondences, consonant errors, vowel digraphs, etc.). Overall, the typically developing children produced the most errors in orthography, followed by phonology, with the fewest errors being attributed to morphology. Four major linguistic feature error patterns emerged involving vowel errors, letter doubling confusion, misspelled derivational suffixes, and sonorant cluster reduction. Spelling performance on the experimental spelling measure was correlated with age, but was not correlated with parents' educational level or language-related subtests. Younger children made more errors than older children in all morphological categories.

Findings supported the importance of qualitative investigations of spelling errors in order to effectively characterize linguistic skill in spelling.