| ACKNOWLEDGEMENTS | 第1-8页 |
| ABSTRACT | 第8-10页 |
| 中文摘要 | 第10-15页 |
| List of Tables and Figures | 第15-17页 |
| Chapter One INTRODUCTION | 第17-21页 |
| ·Need for the Present Study | 第17-19页 |
| ·Outline of the Thesis | 第19-21页 |
| Chapter Two LITERATURE REVIEW | 第21-40页 |
| ·Introduction | 第21页 |
| ·Basic Concepts | 第21-26页 |
| ·Second language vocabulary acquisition | 第21-22页 |
| ·Tasks for L2 vocabulary acquisition | 第22-26页 |
| ·Definition of 'task' in SLA | 第23-24页 |
| ·Main features of tasks in SLA | 第24-26页 |
| ·Studies on Task-based L2 Vocabulary Acquisition | 第26-31页 |
| ·Theoretical studies | 第26-27页 |
| ·Empirical studies on task-based L2 vocabulary acquisition | 第27-31页 |
| ·Effects of task type on L2 vocabulary acquisition | 第27-30页 |
| ·Effects of task frequency on L2 vocabulary acquisition | 第30-31页 |
| ·Involvement Load Hypothesis | 第31-38页 |
| ·Theoretical basis | 第31-33页 |
| ·Construct of task-induced involvement | 第33-35页 |
| ·Assumptions of the Hypothesis | 第35页 |
| ·Empirical studies on the Hypothesis | 第35-36页 |
| ·Weakness of the Hypothesis | 第36-38页 |
| ·Summary | 第38-40页 |
| Chapter Three METHODOLOGY | 第40-56页 |
| ·Introduction | 第40页 |
| ·The Pilot Study | 第40-45页 |
| ·Research questions | 第40-41页 |
| ·Subjects | 第41页 |
| ·Research design | 第41-42页 |
| ·Major findings | 第42-44页 |
| ·Limitations | 第44-45页 |
| ·Solutions in the main study | 第45页 |
| ·The Main Study | 第45-56页 |
| ·Research questions | 第45-46页 |
| ·Subjects | 第46-47页 |
| ·Research design | 第47页 |
| ·Materials | 第47-50页 |
| ·Treatment text and target words | 第47-49页 |
| ·Tasks | 第49-50页 |
| ·Instruments and procedures | 第50-54页 |
| ·Instruments | 第51-52页 |
| ·Procedures | 第52-54页 |
| ·Data collection and analysis | 第54-56页 |
| Chapter Four RESULTS AND DISCUSSIONS | 第56-78页 |
| ·Introduction | 第56页 |
| ·Effects of Task Type | 第56-62页 |
| ·Overall effects of task type | 第56-57页 |
| ·Effects of specific tasks | 第57-60页 |
| ·Effects of input and output tasks | 第60-61页 |
| ·Summary of major findings | 第61-62页 |
| ·Effects of Task Frequency | 第62-69页 |
| ·Overall effects of task frequency | 第62-64页 |
| ·Effects of task frequency on each EG's vocabulary learning | 第64-66页 |
| ·Interaction between task frequency and task type | 第66-69页 |
| ·Summary of major findings | 第69页 |
| ·Discussion | 第69-78页 |
| ·Role of Involvement Load Hypothesis | 第69-73页 |
| ·Reassessing the Involvement Load Hypothesis | 第73-78页 |
| ·Difficulty in determining the involvement load | 第73-74页 |
| ·Difficulty in manipulating the involvement load | 第74-75页 |
| ·Role of input and output in the involvement load | 第75-78页 |
| Chapter Five FINDINGS,IMPLICATIONS AND LIMITATIONS | 第78-83页 |
| ·Introduction | 第78页 |
| ·Major findings | 第78-80页 |
| ·Findings relating to the effects of task type on L2 vocabulary learning | 第78-79页 |
| ·Findings relating to the effects of task frequency on L2 vocabulary learning | 第79-80页 |
| ·Implications | 第80-81页 |
| ·Theoretical implications | 第80页 |
| ·Pedagogical implications | 第80-81页 |
| ·Limitations and Recommendations for Future Research | 第81-83页 |
| REFERENCES | 第83-89页 |
| APPENDIX Ⅰ Treatment Text for Task 1,3 and 4 | 第89-90页 |
| APPENDIX Ⅱ Treatment Text for Task 2and 5 | 第90-91页 |
| APPENDIX Ⅲ Comprehension Questions for Task 1 and 2 | 第91-92页 |
| APPENDIX Ⅳ Cloze for Task 3 | 第92-93页 |
| APPENDIX Ⅴ Sentence-making for Task 4 and 5 | 第93-94页 |
| APPENDIX Ⅵ Pretest for Target Words | 第94-97页 |
| APPENDIX Ⅶ Vocabulary Acquisition Test after 4 Runs | 第97-99页 |
| APPENDIX Ⅷ Interview Questions | 第99-100页 |
| APPENDIX Ⅸ 攻读硕士学位期间发表的论文 | 第100页 |
