The Effect Of Task Complexity On Linguistic Performance In L2 Speaking And Writing

Since Robinson's Cognition Hypothesis was proposed,a lot studies examining the effect of task complexity on L2 learners' performance have demonstrated that task performance is influenced by task complexity.However,most previous studies focused on manipulating task complexity only in either written mode or spoken mode,which indicates few studies have combined task complexity with task mode.The current study tried to fill this gap by setting out to investigate the effect of task complexity and task mode on L2 learner's language performance within the theoretical framework of Cognition Hypothesis.Three research questions were addressed: 1)To what extent does task complexity affect L2 learners' output in speaking and writing task respectively in terms of accuracy,syntactic complexity and lexical variety? 2)Is there any difference between learners' task performance in writing and speaking tasks under the condition of different task complexity? If so,how is learners' performance affected by mode? 3)Are there any interaction effects between task complexity and task mode on learners' task performance?To answer the above questions,an empirical study was conducted via picture narration tasks involving two degrees of task complexity,i.e.,a structured task being more simple and an unstructured task being more complex,and two modes,i.e.,spoken mode and written mode.Forty-one participants were English major students from Guangdong University of Foreign Studies,whose English proficiency were upper-intermediate,and were randomly divided into a simple group and a complex group.Then participants in each group completed two tasks with same complexity in both spoken and written modes within a time limit,5 minutes for speaking task and 25 minutes for writing.As a result,a total number of eighty-two pieces of data was collected for further analysis with respect to accuracy,syntactic complexity and lexical variety.The statistical analysis revealed the following results: 1)With the increase of task complexity along resource-dispersing dimension by manipulating the variable of task structure in the current study,only accuracy in written mode was significantly affected by task complexity.2)Learners' performance of accuracy and lexical variety were significantly affected by task mode no matter in the simple task or the complex task.Specifically,more accurate output and more diverse vocabularies were produced in written mode than in oral mode regardless of task complexity.3)Significant interactional effect of task complexity and task mode was not found in all three aspects except for accuracy.The results of the current research partially supported Robinson's Cognition Hypothesis in terms of syntactic complexity,and it has provided more empirical data for the hypothesis and might have some implications for real classroom task design.Also it might suggest that although task complexity is the major basis for proactive pedagogic task sequencing in task-based approaches to syllabus design as Robinson(2003)proposed,task mode should also be taken into consideration during task design in order to exert students' language potential to the greatest extent.