The Effects Of Planning And Working Memory Capacity On L2 Oral Production

With the rise of task-based teaching,the field of SLA has done a number of researches on task,specifically speaking,on task complexity and task difficulty.Task complexity is the cognitive task features that can be manipulated either to enhance or reduce cognitive demands imposed on the learners when they complete a task.And task difficulty emphasizes learners' perception of the demands of the task,and these are determined by both affective factors and by ability variables.In the past thirty years,a considerable body of researches have explored the effects of task complexity on SLA,especially the effects of planning on the L2 learners' oral production.Most studies have revealed that planning has positive effects on oral performance.However,there is still controversy on the effects of different types of task planning.On the other hand,as an ability variable in task difficulty,working memory has also been widely explored,but the current results are still in great dispute.Planning is an external factor reflecting task complexity,and working memory is learner's internal factor,nevertheless,few studies have been conducted to explore the interaction of task planning and working memory on L2 oral production.Based on Robinson's Cognitive Hypothesis(2001a,2005,2007,2011,2015)and Skehan's Limited Attentional Capacity Model(1998,2001,2005),the research aims to investigate the influence of task complexity and task difficulty on L2 oral production from perspectives of task planning and working memory.Research questions are shown as follows:(1)How does different task planning(no planning,pre-task planning and online planning)affect L2 learners' oral production in terms of accuracy,complexity and fluency?(2)How does working memory capacity affect L2 learners' oral production in terms of accuracy,complexity and fluency?(3)How do different task planning and working memory capacity interactively affect L2 learners' oral production in terms of accuracy,complexity and fluency?The participants in this study were 116 sophomores from English majors at Huang he Science and Technology College.First of all,6 students were selected randomly to attend the pilot experiment,and the other 110 students participated the main experiment.110 subjects took part in the working memory capacity test firstly.According to the test results,their working memory capacity was divided into three levels: high WMC,middle WMC and low WMC.The subjects in middle WMC were removed,and the remained 74 subjects were divided into 6 groups in terms of different task(no planning,pre-task planning and online planning)and working memory capacity(high WMC,low WMC).Pretest of oral production ensured there were no significant differences between subjects of 6 groups in terms of accuracy,complexity and fluency.The main study was a picture narration test.At last,the researcher randomly selected 2 subjects in each group to conduct an interview,and others filled in the questionnaires.The results are shown as follows:Firstly,compared with no planning group,pre-task planning enhanced accuracy and syntactic complexity of L2 oral production,and online planning led to higher syntactic complexity of L2 oral production,and its effect on accuracy was close to significance.The lexical complexity in no-planning group and pre-task planning group was significantly higher than that in on-line planning group.Secondly,working memory capacity had a significant effect on the accuracy of L2learners' oral production,the accuracy of learners with high WMC was higher than that of learners with low WMC.But research did not reveal the significant effect of WMC on the complexity and fluency of L2 learners' oral production.Thirdly,there was no interaction between planning and WMC on L2 oral production in terms of accuracy,complexity and fluency.In other words,WMC could not restrict the effects of planning on L2 oral production.The research findings partly support Skehan's Limited Attentional Capacity Model,for there was a trade-off effect between language form(accuracy and complexity)and language meaning(fluency).The results also partly support Robinson's Cognitive Hypothesis,for the attention was not the only factor influencing the production.In addition,the results was also influenced by task features,learners' proficiency and their learning strategy,learners' cognitive resources,learners' tendency.The findings of the study have an implications on second language pedagogy.L2 teachers should realize the impact of planning time on learners' oral production,especially providing planning time before oral performance.Though allowing learners to plan while performing improves the oral production,the effect is not better than pre-task planning.On the other hand,foreign language teachers ought to pay attention to learners' individual differences,especially the effect of WMC on learners' oral production,so they can adopt different teaching methods towards different learners.In addition,teachers should concern the interactive effects of internal and external factors on L2 learners' speech performance in order to achieve the best pedagogical effects.