Data_Sheet_1_A Dynamic Systems Study on Complexity, Accuracy, and Fluency in English Writing Development by Chinese University Students.doc

This study investigated the development of lexical complexity, sentence complexity, accuracy, and fluency in the English writing of 22 Chinese university students from the perspective of Complex Dynamic Systems Theory (CDST). Compositions were assigned 30 times over the course of one academic year through Pigaiwang, an online platform that automatically evaluates writing. A modified retrodictive modeling approach was adopted. Specifically, a longitudinal cluster analysis was used to examine emergent prototypes. A moving correlation analysis and retrodictive interviews were conducted to study the signature dynamics that produce each prototype. At each collection, the 22 student compositions were classified into two clusters. One cluster contained those students who performed better than average in accuracy, but worse in the other three variables. The other cluster comprised those students with the opposite performance. Students moved continuously between the two clusters; and their change trajectories can be categorized into three prototypes: a continuously stable type, an initially variable and then stable type, and a continuously variable type. Case studies of three students representing the three emergent prototypes indicated that the signature dynamics for the three prototypes were related to dynamic interactions among different variables and dynamic changes in affect-related elements in the form of writing interests, motivation, and strategies. The initial conditions and the feedback from Pigaiwang acted as key control parameters in shaping the prototypes. The continuously variable prototype developed their writing proficiency to the greatest extent and had the most variability. Based upon the findings, implications for teaching L2 writing are discussed.

本研究基于复杂动态系统理论（Complex Dynamic Systems Theory, CDST），探究了22名中国大学生英语写作中的词汇复杂度、句法复杂度、准确度与流畅度的发展特征。本研究在一个学年内，通过自动作文评分在线平台批改网（Pigaiwang）累计收集学生作文共30次，并采用了改进的回溯建模方法。具体而言，本研究通过纵向聚类分析检验涌现的原型类别，并借助移动相关分析与回溯式访谈，探究驱动各类原型形成的特征性动态机制。每次作文收集环节，22名学生的作文均被划分为两个聚类簇：其中一个聚类簇的学生在写作准确度上优于平均水平，但在其余三项指标上表现更差；另一个聚类簇的学生则呈现完全相反的表现。学生会在两个聚类簇间持续迁移，其变化轨迹可划分为三类原型：持续稳定型、初始波动后趋稳型，以及持续波动型。针对三类涌现原型各选取一名学生进行个案研究，结果显示，三类原型的特征性动态机制与不同变量间的动态交互，以及以写作兴趣、动机与策略为表现形式的情感相关要素的动态变化密切相关。初始状态与批改网（Pigaiwang）提供的反馈，是塑造各类原型的关键控制参数。其中持续波动型学生的写作熟练度提升幅度最大，且各项指标的波动程度也最高。最后，本研究基于上述发现，探讨了其对第二语言写作教学的启示。