Constructional complexity as a predictor of Korean EFL learners' writing proficiency.

Based on usage-based constructionist approaches to language development, this study investigates the validity of constructional complexity as a predictor of writing proficiency of Korean EFL learners. We analyzed argumentative essays produced by Korean EFL learners and compared a prediction model that uses English argument structure constructions with a conventional T-unit-based model. We first tested the predictive power of a discriminant function model with argument structure constructions as predictors for assessing writing proficiency of lower- and higher-level learners. We then compared the construction-based model to another model that included T-unit measures as predictors. The results validated the contribution of argument structure constructions for predicting L2 writing proficiency: The construction-based model yielded higher prediction accuracy than the T-unit-based model did, confirming that constructional complexity is closely aligned with writing proficiency. These findings demonstrate the significance of a construction-based model as a reliable tool for diagnosing EFL learners' writing proficiency. [ABSTRACT FROM AUTHOR]