Studies exploring complexity, accuracy, and fluency (CAF) development from a complex dynamic or dynamic usage-based (DUB) systems view are well documented in the literature (Verspoor et al., 2021). However, the analyses in these studies are mostly limited to elementary to intermediate level L2 learners from instructed secondary school settings. The current study thus investigates the relationship between time and holistic judgments of proficiency and syntactic and lexical complexity development in the writings of a group of advanced sojourners during a semester spent abroad, addressing the empirical gaps pertained to different proficiency levels and context. The data are weekly diary entries produced over the course of a 12–17 week stay abroad. The data are analyzed for holistic proficiency gains and syntactic and lexical complexity measures through linear mixed-effects modelling. The results confirm the significance of random individual variation, but also suggests a common developmental path as the participants ended up with significant gains in their holistic proficiency but with more elaborate sentences with fewer verb phrases and less diverse vocabulary.

从复杂的动态或基于动态使用的 (DUB) 系统视图探索复杂性、准确性和流畅性 (CAF) 开发的研究在文献中有详细记录（Verspoor 等人，2021）。然而，这些研究中的分析主要局限于受过指导的中学环境中的初级到中级 L2 学习者。因此，当前的研究调查了一组高级旅居者在国外度过的一个学期期间的作品中时间和对熟练程度以及句法和词汇复杂性发展的整体判断之间的关系，解决了与不同熟练程度和背景相关的经验差距。这些数据是在国外逗留 12-17 周期间产生的每周日记条目。通过线性混合效应建模，分析数据以获得整体熟练程度的提高以及句法和词汇复杂性测量。结果证实了随机个体差异的重要性，但也表明了一条共同的发展路径，因为参与者最终在整体熟练程度方面取得了显着进步，但句子更复杂，动词短语更少，词汇种类更少。