The purpose of this study was to examine multiple dimensions of written language produced by eighty-nine children in grades 2, 3, and 4 in narrative and expository writing samples. Two written composition samples were collected from students exhibiting typical development in second, third, and fourth grades using one narrative and one expository writing prompt via a scripted, generated elicitation method. Additionally, participants completed group-administered, norm-referenced measures of receptive vocabulary, word level reading, and reading comprehension. The writing samples were transcribed into Systematic Analysis of Language Transcripts (SALT; Miller & Chapman, 2005), coded, and analyzed for developmental progression of linguistic elements represented by the five factors of productivity, grammatical complexity, grammatical accuracy, lexical diversity, and macrostructure. Reading comprehension scores were used as covariates in the multivariate analyses of variance.

Results indicated that levels of productivity and macrostructure increased steadily with age. Across the narrative and expository samples examined, levels of productivity were highly correlated and nearly equivalent within each grade, whereas a trend was noted for levels of macrostructure in the expository genre to increase more sharply from second to third grade than in the narrative genre. There was a grade effect for grammatical complexity in the expository genre, whereas there were no significant differences between grade levels for narrative grammatical complexity. Interestingly, the second graders scored higher than the third and fourth graders on measures of grammatical complexity (especially MLTu) in their expository samples. Comparison of grammatical complexity levels across genres revealed a small, negative correlation across all three grade levels. No grade level differences were detected for grammatical accuracy and lexical diversity in either genre; although, there was a trend for fourth graders to produce a higher number of grammatical errors than second and third graders. Students in each grade performed similarly regardless of genre type on measures of grammatical accuracy and lexical diversity. Relations among measures of microstructure and macrostructure were revealed between productivity and macrostructure in both genres and between macrostructure and grammatical accuracy in the expository genre. Inter-correlations of measures within grade level are discussed. There were no significant effects of ethnicity, socioeconomic status, or gender on writing outcomes. Interestingly, trade-offs in performance on certain linguistic features appeared to occur for second and fourth graders.

Results of this study suggest that variables of written microstructure and macrostructure were sensitive to grade and genre level differences, that productivity (a measure of microstructure), and macrostructure were related in both genres for all three grade levels, and that one cannot assume the older students will outperform younger students on all measures. This latter finding was thought to be due to a trade-off between linguistic and cognitive demands for second and fourth graders. Consequently, future research needs to establish these trade-off trends occur in larger samples and examine the effects of different academic contexts (e.g., variable elicitation techniques, discourse structures, content specific assignments) on this phenomenon. The findings of this investigation are discussed in light of grade level standards for writing and the identification of students with writing difficulties. Multiple suggestions are presented for educational implications of the results, and specific directions provided for future research.