136 / 2021-06-29 13:13:29

Effects of Task Complexity on Doctoral Candidates’ L2 Lexical Development in Academic Writing from the CDST perspective

CDST,doctoral candidates,language production,L2 lexical development

Task complexity researches concerned about language production and development (Robinson, 2011). Previous empirical studies at home mainly focused on the relationship between task complexity and learner’ language production. Existed findings confirmed that tasks complexitycontributed to learners’ overall language production (Xing & Liu, 2016).Complex dynamic systems theory (CDST) proposed and valued the variability of language production in a changing language system over time (Larsen-Freeman, 2009). Accordingly, learners’ use of individual words can be tracked to explore variability patterns in their lexical production, which can be regard as a complex adaptive system (Zheng, 2020).However, few studies have explored doctoral candidates’ L2 lexical development in academic writing from the perspective of CDST.

This study is designed to investigate30 Chinese doctoral candidates’ (degree of engineering) L2 lexical development in academic writing through 8 weeks from the CDST perspective. Learners’ individual words were organized in several corpus that can import in lexical calculator software and numericized into indices in terms of lexical diversity, density and sophistication. Indices were then analyzed by SPSS (24.0) and the results indicated that: lexical diversity and density fluctuated while lexical sophistication decreased in general; a competitive relationship between lexical diversity and sophistication was identified. Current findings suggested that different dimensions of doctoral candidates’ L2 lexical use demonstrated complex features and constituted a dynamic L2 lexical system. Results of this study would shed lights on further L2 lexical studies.