Coordination of linguistic subsystems as sign of automatization?

For the current study, two learners were selected from a previous study (Hou, Verspoor & Loerts, 2016), one who had shown marked improvement and one who had stagnated. Their twelve successive writings were analyzed on holistically scored measures in complexity, accuracy, fluency, idiomaticity and coherence (CAFIC) and on two analytical measures to operationalize syntactic and lexical complexity. Their developmental trajectories were explored from a dynamic perspective with visual graphs (LOESS curves), Monte Carlo analyses and correlational analyses. The overall findings were that the good learner showed rather synchronous development in most of the measures and a significant jump in lexical complexity (operationalized as average word length), suggesting a level of automaticity of the system as whole, which allowed her to make progress in one specific linguistic subsystem which usually occurs at the advanced stages (cf. Penris & Verspoor 2017). The weaker learner, on the other hand, showed more competitive or random patterns in almost all measures. The only synchronous development was found in accuracy and idiomaticity, suggesting that lower accuracy scores were related to non-idiomatic language use. The weak learner also showed significantly more variability than the good learner in syntactic complexity (operationalized as finite verb ratio).