| ACKNOWLEDGEMENTS | 第8-9页 |
| ABSTRACT | 第9页 |
| 摘要 | 第10-15页 |
| Chapter Ⅰ INTRODUCTION | 第15-19页 |
| 1.1 Background of the Research | 第15-16页 |
| 1.2 Research Questions | 第16页 |
| 1.3 Significance of the Study | 第16-17页 |
| 1.4 Organization of the Study | 第17-19页 |
| Chapter Ⅱ LITERATURE | 第19-35页 |
| 2.1 Definitions of Language Attrition and Some Other Related Terms | 第19-20页 |
| 2.2 A Typology of Language Attrition Studies | 第20-22页 |
| 2.2.1 Two Distinctions Provided by Weltens | 第20-21页 |
| 2.2.2 Specific Distinctions Provided by Van Els | 第21-22页 |
| 2.3 Theories in Second Language Attrition | 第22-27页 |
| 2.3.1 The Regression Hypothesis | 第22-24页 |
| 2.3.2 The Inverse Hypothesis | 第24-25页 |
| 2.3.3 The Critical Threshold Hypothesis | 第25-26页 |
| 2.3.4 The Linguistic Feature Hypothesis | 第26-27页 |
| 2.4 Variables Related with the Process of Language Attrition | 第27-30页 |
| 2.4.1 Three Variables Concluded by Weltens | 第27页 |
| 2.4.2 The Variables Summarized by Ni Chuanbin | 第27-28页 |
| 2.4.3 Three Important Variables | 第28-30页 |
| 2.5 Studies on the Attrition of Lexical Knowledge | 第30页 |
| 2.6 Language Learning Strategies | 第30-35页 |
| 2.6.1 Definitions of Learning Strategies | 第31-32页 |
| 2.6.2 Classifications of Learning Strategies | 第32页 |
| 2.6.3 Vocabulary Learning Strategies | 第32-35页 |
| Chapter Ⅲ RESEARCH METHODOLOGY | 第35-42页 |
| 3.1 Research Design | 第35-36页 |
| 3.2 Subjects | 第36页 |
| 3.3 Instruments | 第36-40页 |
| 3.3.1 Questionnaire | 第36-38页 |
| 3.3.2 Vocabulary Test | 第38-39页 |
| 3.3.3 Pilot Study | 第39-40页 |
| 3.4 Data Collection | 第40-41页 |
| 3.5 Data Analysis | 第41-42页 |
| Chapter Ⅳ RESULT | 第42-58页 |
| 4.1 The Relation between Vocabulary Attrition and Initial Language Proficiency | 第42-46页 |
| 4.1.1 T-test of Two Times’Vocabulary Tests Score | 第42-43页 |
| 4.1.2 Differences in Attrition Degrees within Different Language Proficiency Groups | 第43-45页 |
| 4.1.3 The Association between Vocabulary Attrition and Final Language Proficiency | 第45-46页 |
| 4.2 Comparison between High Attrition Group and Low Attrition Group in VLS Use | 第46-53页 |
| 4.2.1 The General Situation of Students’VLS Use | 第46-48页 |
| 4.2.2 The Comparison of VLS Use between High Attrition Group and Low Attrition Group | 第48-53页 |
| 4.2.2.1 Overall Comparison between Two Groups | 第48-49页 |
| 4.2.2.2 Specific Comparison between Two Groups | 第49-53页 |
| 4.3 The Relation between the Vocabulary Attrition and VLS | 第53-58页 |
| 4.3.1 The Correlation between Metacognitive Strategy and Vocabulary Attrition | 第53-55页 |
| 4.3.2 The Correlation between Cognitive Strategy and Vocabulary Attrition | 第55-56页 |
| 4.3.3 The Correlation between Social | 第56-58页 |
| Chapter V DISCUSSIONS AND IMPLICATION | 第58-66页 |
| 5.1 Discussions | 第58-62页 |
| 5.1.1 Language Attrition after Six Months’Disuse of Target Language | 第58-59页 |
| 5.1.2 The Relationship between Language Attrition and Final Language Proficiency | 第59-60页 |
| 5.1.3 Difference in VLS Application between High Attrition Group and Low Attrition Group | 第60-62页 |
| 5.1.4 The VLS Significantly Correlated with Vocabulary Proficiency Maintaining | 第62页 |
| 5.2 Implications | 第62-64页 |
| 5.3 Limitations and Suggestions for the Further Study | 第64-66页 |
| CONCLUSION | 第66-68页 |
| BIBLIOGRAPHY | 第68-75页 |
| APPENDIX Ⅰ | 第75-78页 |
| APPENDIX Ⅱ | 第78-81页 |
