| Abstract | 第1-8页 |
| 摘要 | 第8-9页 |
| Acknowledgements | 第9-12页 |
| Chapter 1 Introduction | 第12-18页 |
| ·Background of the Research | 第12-15页 |
| ·Meaning of the Research | 第15-16页 |
| ·Layout of the Thesis | 第16-18页 |
| Chapter 2 Literature Review | 第18-38页 |
| ·Input Hypothesis and Acquisition | 第18-19页 |
| ·Output Hypothesis and Acquisition | 第19页 |
| ·Definition of Lexical Richness | 第19-20页 |
| ·Lexical Richness Measures | 第20-32页 |
| ·Measures of Lexical Variation | 第21-25页 |
| ·Measures of Lexical Sophistication | 第25-27页 |
| ·Measures of Lexical Density | 第27-29页 |
| ·Measures of Lexical Error | 第29-32页 |
| ·Previous Studies on Lexical Richness | 第32-38页 |
| ·Previous Studies Abroad | 第32-35页 |
| ·Previous Studies at Home | 第35-38页 |
| Chapter 3 Research Methodology | 第38-43页 |
| ·Research Questions | 第38页 |
| ·Paricipants of the Research | 第38-39页 |
| ·Research Methods | 第39页 |
| ·Research Procedures | 第39-43页 |
| Chapter 4 Data Analysis and Discussion | 第43-56页 |
| ·Results of Four Dimensions of Lexical Richness | 第43-52页 |
| ·Results of Lexical Variation | 第43-45页 |
| ·Results of Lexical Sophistication | 第45-48页 |
| ·Results of Lexical Density | 第48-51页 |
| ·Results of Lexical Error | 第51-52页 |
| ·Evaluation of the Writing Quality | 第52-53页 |
| ·Relationship between Lexical Richness and Writing Quality | 第53-54页 |
| ·Discussion | 第54-56页 |
| Chapter 5 Conclusions | 第56-63页 |
| ·Major Findings | 第56-57页 |
| ·Limitations of the Research | 第57页 |
| ·Implications of the Research | 第57-63页 |
| ·Implications for Vocabulary Teaching | 第58-60页 |
| ·Implications for Vocabulary Learning | 第60-61页 |
| ·Implications for Teaching Writing | 第61-62页 |
| ·Implications for Further Researches | 第62-63页 |
| References | 第63-67页 |
| Appendix Ⅰ Samples of the First Writing Assignment | 第67-70页 |
| Appendix Ⅱ Samples of the Second Writing Assignment | 第70-73页 |
