| This study examines the latent structure of syntactic complexity as a multidimensional construct in L2 timed argumentative essays and aims to explore its effect on writing quality through the application of structural equation modeling(SEM).Syntactic complexity,understood broadly as the variety and sophistication in language use,has become a prominent construct in the assessment of L2 writing performance and language development.However,there is yet to be a fully agreed-upon operational definition of this construct due to its high complexity and multidimensionality.In addition,it remains unclear how it affects writing quality in the register of timed argumentative writing.To investigate syntactic complexity and its sub-dimensions,exploratory and confirmatory factor analyses were performed on 4560 unrated L2 argumentative essays from International Corpus Network of Asian Learners of English(ICNALE).Fourteen large-grained indices provided by L2SCA(L2 Syntactic Complexity Analyzer,Lu,2010),31 fine-grained indices of clausal complexity and 66fine-grained indices of phrasal complexity provide by TAASSC(Tool for the Automatic Assessment of Syntactic Sophistication and Complexity,Kyle,2016)were used to measure syntactic complexity of the essays.To explore the effect of syntactic complexity on writing quality,SEM was conducted on another 640 rated L2 argumentative essays.Main findings of the study include: first,a second-order syntactic complexity model was found to fit the data.Syntactic complexity in L2 timed argumentative writing was found to be a multi-dimensional construct composed of two sub-constructs: clausal subordination and sub-clausal complexity.In addition,sub-clausal complexity is found to be composed of three lower-level sub-constructs: 1)sub-clausal complexity via nominal phrase elaboration(without nominal complement);2)sub-clausal complexity via nominal complement elaboration;3)sub-clausal complexity via non-nominal means.Secondly,clausal subordination was found to have a relatively small effect(β=0.16)on the quality of L2 timed argumentative writing while sub-clausal complexity had a medium positive effect(β=0.66)on writing quality.Findings of the study provide empirical evidence for the multidimensionality of syntactic complexity in L2 argumentative writing and the impact that syntactic complexity has on writing quality. |
