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.

The goal of this study was to examine the spelling errors of children with Autism Spectrum Disorder (ASD) when asked to spell morphologically complex words. Specifically, this study sought to determine if percent accuracy across morphological areas would be similar to patterns noted in typical developing children, correlate with participant age, and correlate to performance on standardized measures of achievement. Additionally, the study wanted to highlight the types of errors made by children with ASD on homonyms and the specific linguistic patterns noted when spelling derivational and inflectional word types. Participants included 29 children diagnosed with Autism, PDD-NOS, and Asperger’s Disorder, ages 8-15 years. The spelling protocol consisted of 36 words differing in morphological complexity, including homonyms, inflections and derivations. The derivational categories included: no shift, orthographic shift, phonologic shift, and orthographic + phonologic shift words (Carlisle, 2000). Spelling errors were analyzed both quantitatively and qualitatively. The qualitative analysis used a unique coding system, the Phonological, Orthographic, and Morphological Analysis of Spelling (POMAS; Silliman et al., 2006), which identified both the linguistic category of an error, as well as the specific linguistic feature in error. Results indicated that the spelling errors of children with ASD seemed to follow a developmental pattern that was similar to typically developing children (Carlisle, 1988; 2000). To be specific, phonologic and orthographic+phonologic shift categories evidenced significantly more errors than the no shift, orthographic shift, and inflections categories, which were not significantly different from each other. As expected, academic achievement, as measured by letter-word decoding, spelling, and age, were correlated with morphological spelling ability. Findings supported the use of the POMAS as a coding measure sensitive to spelling error patterns found in children with ASD. Several common feature errors emerged including: 1) vowel errors, 2) consonant deletions, 3) letter doubling, 4) derivational suffix errors, and 5) whole word substitutions. Overall, this heterogeneous group of spellers fit into three profiles of spelling ability: 1) competent spelling ability, 2) morphologically challenged spellers, and 3) generally challenged spellers. Hence, qualitative investigations of spelling errors play a crucial part in the characterization of spelling skill in children with ASD.

Previous research investigations in the area of spelling development have adopted two approaches, the broad approach and the narrow approach. The broad approach suggests that spelling develops in sequential stages whereas the narrow approach focuses on individual linguistic patterns. However, research findings have revealed that children’s spellings do not exhibit errors pertaining to specifically one stage or reflecting one linguistic element, yet a research void exists in resolving how these two approaches might intermix. This study examined the spelling errors of typically developing children in first through fourth grades (N = 400) to determine the quantitative and qualitative differences in misspellings among grade levels. Each grade level had an equal representation of children (N = 100) and male and female participants. The spelling errors were extracted from two writing samples completed by the children, a narrative and expository sample. In an attempt to combine the broad and narrow approaches, a coding system was designed to evaluate the linguistic category (phonological, orthographic, morphological) and specific features (letter name spelling, vowel error, digraph, etc.) of the spelling errors. The findings revealed a significant interaction between grade level and error type for phonologically-based spelling errors (1 st graders made more errors than 2nd and 4th graders) and a greater number of morphological errors was noted in 4 th vs. 2nd grade. No significant effects were noted for writing genre or gender. Analysis of performance patterns for specific linguistic category errors within and across grade levels revealed that all four grade levels committed the most phonological errors in the PSE (phonological – silent /e/) and PSON (phonological – sonorant clusters) categories. The OLN (orthographic – letter name) and ODI (orthographic – digraph) errors also occurred frequently in all four grades with first graders demonstrating significantly more occurrences of the OLN than ODI error. Morphological findings revealed that first graders made significantly more MINF (morphological – inflection) than MHOM (morphological – homonym) errors and all four grades had significantly more MINF than MCON (morphological – contraction) errors. A qualitative analysis regarding the most frequently misspelled words and most frequently encountered codes was also performed. The clinical and educational implications of these findings are discussed.