The Effects Of Working Memory Capacity And Task Complexity On EFL Learners' Argumentative Writing Performance

L2 writing is not only one of the most convincing indexes to show EFL learners'language proficiency,but also crucial for Chinese students in their academic researches and daily life.Researches on the individual factors which could influence EFL learners' writing performance play a critical role in second language acquisition.Thus,this study aims to explore the effects of working memory capacity and task complexity on EFL learners' argumentative writing performance.It addresses the following research questions:1.Is there any significant effect of working memory capacity on EFL learners'argumentative writing performance?2.Is there any significant effect of task complexity on EFL learners'argumentative writing performance?3.Does the effect of task complexity on EFL learners,argumentative writing performance vary according to working memory capacity?This study adopted a 2(working memory capacity)× 4(task complexity)two-way ANOVA design.80 non-English majors of same language proficiency from Nanjing Tech University were involved in this study.According to their working memory capacity,all the participants were divided into two different working memory groups,i.e.,high working memory capacity group(HWMC:N=40)and low working memory capacity group(LWMC:N=40).Participants' working memory capacity was measured by a Chinese computerized reading span test(CCRST).The test covered three indexes of working memory,i.e.,information processing,information storage and reaction time.The variable of task complexity was manipulated along both resource-directing dimension(?/-few elements)and resource-dispersing dimension(+/-planning time).Then four groups of participants received similar tasks of varying complexity:15 minutes of planning time and 4 elements;5 planning time and 4 elements;5 minutes of planning time and 8 elements;15 minutes of planning time and 8 elements.As the planning time decreases and the number of elements increases,the task complexity increases.The writing sample was elicited through an argumentative writing task which was assigned to the participants on a topic of dating show.The writing materials were adapted from a task used in Michel's(2011)study.The participants' argumentative writing production was measured in terms of accuracy(i.e.EFC/C),fluency(i.e.Dys/W),lexical complexity(i.e.type/token ratio,)and syntactic complexity(i.e.C/T).The major findings of the present study are displayed as follows:1.Working memory capacity influences EFL Learners,argumentative writing performance significantly in terns of accuracy and syntactic complexity.The results of two-way ANOVA revealed a significant main effect of working memory capacity on EFL learners' argumentative writing performance(for accuracy;F(1,72)=19.158,p<.05,?2=.210,for syntactic complexity:F(1,72)=4.218,p<.05,?2=.055).Findings suggest that learners with higher working memory capacity gain better accuracy and syntactic complexity in their argumentative writing production.2.Task complexity influences EFL Learners' argumentative writing performance significantly in terms of accuracy,fluency and lexical complexity(for accuracy:F(3,72)=6.408,p<.05,?2=.211,for fluency:F(3,72)=23.553,p<.05,?2=.495,for lexical complexity:F(3,72)=8.320,p<.05,?2=.257).Findings suggest that the accuracy,fluency and lexical complexity of learners' argumentative writing performance is greatly affected different task conditions.3.No significant interaction effect between working memory capacity and task complexity on EFL learners,argumentative writing performance is observed(for accuracy:F(3,72)= 1.047,p>.05,?2=.042;for fluency:F(3,72)=.476,p>.05,?2=.019;for lexical complexity:F(3,72)=1.648,p>.05,?2=.064;for syntactic complexity:F(3,72)=2.551,p>.05,?2=.096).To sum up,EFL learners' argumentative writing performance was significantly affected by working memory capacity and task complexity.The above findings could lend well support to theories concerning working memory or task complexity.With a reading span test and an essay writing task,it can be clearly concluded that working memory has positive influence on EFL learners' argumentative writing scores.And also,for language teachers,the current study has important pedagogical implications on task design and task-based language teaching.