This study examined the relationship of different measures of syntactic complexity with rated quality for two genres of text produced by middle school students. It was hypothesized that different measures would be associated with distinct aspects of syntactic complexity; words per clause with greater use of structures more typical of expository texts, and clauses per T-unit with structures more typical of conversational or narrative registers. A sample of 41 seventh and eighth grade students from suburban middle schools composed a narrative and persuasive essays. Texts were rated for quality and coded for syntactic features including words per clause and clauses per T-unit. Syntactic complexity as measured in words per clause was positively correlated with quality for essays but not for narratives. Clauses per T-unit was positively correlated with quality for narratives, but negatively correlated with quality for essays. The relationships between syntactic complexity and text quality were thus found to be dependent both on the genre of the text, and the measure of syntactic complexity used.

Two measures of syntactic complexity, clauses per T-unit and words per clause, were used to examine differences among four genres of text-narrative, descriptive, compare/contrast, and persuasive-written by the same two cohorts (83 students in grades three and five and 96 students in grades five and seven) on two occasions 2 years apart as part of a larger longitudinal study. For clauses per T-unit, a measure of subordination, significant differences were found between persuasive essays, which had more subordinate clauses, and the other three genres. For words per clause, an indicator of the denser syntax of the academic register, significant differences were found between descriptive texts, which had more words per clause than the persuasive essays, which did not differ from the compare/contrast texts. Over the grade levels studied, the measures of syntactic complexity did not increase in their differentiation among the four genres. The two measures of syntactic complexity were negatively correlated, especially for the persuasive essays. For text length, which is thought to reflect compositional fluency, grade, genre, and grade 9 genre effects were significant for both cohorts. Post hoc analyses found few examples of the syntax-level structures characteristic of the academic register. These findings suggest that although students could produce each kind of genre, their ability to do so may have been compromised by their limited knowledge of the syntactic structures required to achieve text-level genre goals. Researchers and educators should consider the syntactic-and text-level requirements for different school-based genres in designing and evaluating writing instruction.

Children in grades one to four completed two sentence construction tasks: (a) Write one complete sentence about a topic prompt (sentence integrity, Study 1); and (b) Integrate two sentences into one complete sentence without changing meaning (sentence combining, Study 2). Most, but not all, children in first through fourth grade could write just one sentence. The sentence integrity task was not correlated with sentence combining until fourth grade, when in multiple regression, sentence integrity explained unique variance in sentence combining, along with spelling. Wordlevel skills (morphology in first and spelling in second through fourth grade) consistently explained unique variance in sentence combining. Thus, many beginning writers have syntactic knowledge of what constitutes a complete sentence, but not until fourth grade do both syntax and transcription contribute uniquely to flexible translation of ideas into the syntax of a written sentence. In Study 3, eleven syntactic categories were identified in single-and multi-sentence composing from second to fifth grade. Complex clauses (independent plus subordinate) occurred more often on single-sentence composing, but single independent clauses occurred more often on multi-sentence composing. For multi-sentence text, more single, independent clauses were produced by pen than keyboard in grades 3 to 7. The most frequent category of complex clauses in multi-sentence texts varied with genre (relative for essays and subordinate for narratives). Thus, in addition to syntax-level sentence construction and word-level transcription, amount of translation (number of sentences), mode of transcription, and genre for multiple sentence text also influence translation of ideas into written language of child writers. Results of these studies employing descriptive linguistic analyses are discussed in reference to cognitive theory of writing development. KeywordsSentence construction; Single-sentence composing; Multi-sentence composing; Syntactic level of language; Written syntax © Springer Science+Business Media B.V. 2010 vwb@u.washington.edu . NIH Public Access Author ManuscriptRead Writ. Author manuscript; available in PMC 2012 February 1. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptA sentence is more easily identified in writing than in speech; yet most speakers of a language appear to know what a sentence is, even though grammarians and linguists continue to grapple with its definition. (Harris & Hodges, 1995, p. 231).Teachers encourage children to write in complete sentences. Yet little is known about developing writers' conceptions of a complete sentence. A sentence is traditionally defined as a group of words that expresses a complete thought, but what is a complete thought? Do beginning writers in first grade and thereafter understand what a complete sentence is? When instructed to write just one sentence, will they write one and only one sentence? When they are asked to combine two sentences into one good sentence without altering ...