Subtypes of written expression in elementary school children: a linguistic-based model.

The purpose of this study was to provide a reliable and valid classification scheme for written expression that captured the linguistic variability present in a typical elementary school sample. This empirically derived classification model was based on the following linguistic-based writing skills: (a) understandability of discourse, (b) grammar, (c) semantics, (d) spelling, and (e) reading comprehension. The sample included 257 fourth-grade (n = 142) and fifth-grade (n = 115) students (46.3% boys, 79.4% White, age range = 8;3-11;7 years; M = 10.10). All of the students were receiving their writing instruction in the regular education setting, with approximately one third receiving some type of educational assistance. The sample fell in the middle socioeconomic stratum. Cluster analytic techniques derived different possible solutions. Results of a series of internal validity studies provided strong evidence that the six-cluster solution was both stable and interpretable, with subtypes reflecting normal as well as writing disability variants. Further, the writing disability subtypes ranged from global impairment to more specific linguistic impediments. Based on their characteristics, the clusters were named (a) Average Writers (n = 102), (b) Low Semantics (n = 31), (c) Low Grammar (n = 18), (d) Expert Writers (n = 33), (e) Low Spelling-Reading (n = 13), and (f) Poor Text Quality (n = 60). Subtypes differed on the percentages of children in selected subtypes manifesting specific writing deficits as well as on selected aspects of measures of metacognition, self-efficacy, and self-regulation of the writing process. Results provide researchers with a foundation to further investigate the underlying neurolinguistic and neurocognitive processes that may strengthen or undermine students' ability to produce a quality written product and to design and implement intervention techniques to address the various subtype patterns inherent in a regular elementary school classroom.