| Since the 1980's, people have gradually realized the significance of the study on the English learning tasks themselves, owing to the upsurge of task-based syllabus and the exploration of the methods to achieve the balanced development of English learners'linguistic forms and meaning. Quite a few English teaching researchers have written books and papers to probe into learning tasks. The researches concerning tasks are concentrated on the following two aspects: first, from the linguistic and pedagogical perspective, the study is centered on how to improve language teaching quality by implementing tasks in the actual classroom; second, from the cognitive and psycholinguistic perspective, the study of the effects of task variables on the learners'language production and development is emphasized. However, how the task variables produce influences on the learners'language production should be firstly worked out in order to solve the problem of how to implement tasks in the actual classroom and how to employ tasks to achieve certain pedagogical goal. Hence it's very important to study the effects of different task types and task features on the learners'language production. Writing, as a kind of language production, is similar to speaking. However, tasks in speaking are often the focus of task researches, tasks in writing are neglected in the past task researches.Based on the model of writing production and the theory of task complexity and task difficulty, this thesis aims to investigate the effects of three different task types and task features on the learners'writing production in terms of fluency, complexity and accuracy by the qusai-experiment method. The three task types consist of personal task, topic task and the summary task, and task features refer to task complexity and task difficulty. The non-English majors at Guangxi Normal University are selected as subjects.The major findings of the present study are: 1) Task types affect learners'writing production. Task types have significant effects on the accuracy, complexity and fluency of writing production. The accuracy of language in personal task is significantly higher than in topic task and summary task; summary task generates significantly more complex language than personal task and topic task; personal task and topic task lead to significantly higher fluency than summary task. 2) Task complexity affects learners'writing production. Task complexity has significant effects on the accuracy, complexity and fluency of writing production. The more complex the task is, the less accurate the writing production is, the less fluent the writing production is, and the more complex the writing production is; the less complex the task is, the more accurate the writing production is, the more fluent the writing production is, and the less complex the writing production is. 3) Task difficulty is partly correlated to learners'writing production. The perception of task difficulty is significantly and negatively correlated to the accuracy and fluency of writing production; stress and the fluency of writing production are significantly and negatively correlated; confidence in ability is significantly and positively correlated to the accuracy of writing production; interest and motivation are not significantly correlated to the learners'writing production.There are five chapters in the thesis. The first chapter is the introduction in which the general background of the study is presented, the significances of the present study are offered and the research questions are raised.Chapter two firstly presents the definition of tasks in writing, task typology and task features, secondly the related issues concerning the effects of task types, task complexity and task difficulty on learners'performance are reviewed, thirdly based on the writing production model constructed by Chen Huiyuan and Wu Xudong, and the theory of task complexity and task difficulty in Robinson's model, the effects of task types and task features on writing production are theoretically analyzed. On the basis of this analysis, research hypotheses are proposed.Chapter three is the design and the project, which involves subjects, instruments, the procedures of experiment, and measures of writing production.Chapter four focuses on analyzing the data from the study and discussing the results.The last chapter concludes the issues investigated in the proceeding chapters, and points out the limitations of present study and suggestions for further study. |