A Study On The Effects Of Task Complexity On The English Written Production In Non-English Major Learners

Task-based language teaching has been widely accepted since1980s which is based on the importance of output hypotheses in favor of language learning. The research of task complexity, as an important part of it, is also popular in the field of second language acquisition. Accuracy, fluency and complexity are three indices of measuring second language level.The research is based on the Robinson’s theory on task complexity, also introducing two models on attentional resource, Cognitive Hypothesis and Limited Attentional Capacity Model. The former asserts that attentional resource is multi-dimension, and with the increasing of task complexity, the complex task produces better effects and accuracy won’t be traded off by complexity, while the latter maintains that there exist trade-off effects among the three aspects of language production. With the rising trend of task complexity, learners have poor performance.The thesis made a study with a combination of quantitative and qualitative analysis method, involving100participants, freshmen from non-English majors, into the task testing and5participants, different language competence according to their performance, as a case study into the interview. What attempts to obtain from the present study is the overall description of the effects of task complexity on written production in terms of accuracy, complexity and fluency.Tasks applied in the study are three narrative tasks with different cognitive load in the conceptualization phase and linguistic encoding. The first task is to narrate the event with the given relative sentence meaning. The second task is to narrate the event with the provision of six related pictures in correct order. The third and most complex task is to design the story plot with the provision of six unrelated pictures without the sequence of usage.Main finding are obtained as follows:First, in the aspect of quantitative research, the results showed that with task complexity increasing, learners produced less accurate(error-free T-units ratio is decreasing and error-free T-units include grammar, lexis, phrase usage and sentence structures), more grammatical complexity (clause usage ratio is increasing)and less lexical complexity(repeated and less complex words are likely to be used), while no significant difference was found in fluency from the group statistics, whereas task complexity had a positive effect on fluency from the individual analysis. In addition, with regard to two aspects of the complexity, there is trade-off effect between grammatical complexity and lexical complexity. To some extent, the results lend support to Skehan’s model which asserts that there are trade-off effects among the three aspects of language production with respect to limited attentional resources. Even trade-off effects exist in the same dimension of complexity.Second, in the aspect of qualitative research, according to what the interviewed students reflect, it is more difficult for them to produce narratives than other genres, because of tenses, inconformity of sentence structures and logical design involved, while taking argumentative writing for example, it could apply many gold structures which make students easy to produce writings. Aiming to this case, low-proficiency students have more desire to consolidate and improve skills by practicing simple genres, while relatively high-proficiency students hope to challenge narratives in order to enlarge their vocabulary and sentence structures. Moreover, avoidance strategy is used by students consciously or unconsciously in the process of production. Lexis is also a key factor in language production. Under the condition of limited time, it is difficult to focus on all aspects of language, just attending to critical aspect.Some implications on English teaching are obtained. Individual difference should be taken into consideration when choosing proper task complexity to make sure students could improve themselves gradually. Teachers should have a good command of avoidance phenomenon to guide students to transform it to the good points. Students should be encouraged to use varied vocabulary, and be taught skills to improve writings, especially in lexical aspect.However, some disadvantages about the study are limited time, relatively small sample size, single tasks, and less special measurements to accuracy, fluency and complexity. But the results are hoped to offer some reference and inspiration for the subsequent research in this field.