| 摘要 | 第1-6页 |
| ABSTRACT | 第6-11页 |
| Chapter 1 Introduction | 第11-15页 |
| ·Importance of Lexical Study | 第11-12页 |
| ·Significance of This Research | 第12-13页 |
| ·Research Objectives | 第13页 |
| ·Overall Structure of the Thesis | 第13-15页 |
| Chapter 2 Literature Review | 第15-31页 |
| ·The Notions of Vocabulary Evaluation | 第15-16页 |
| ·Definition of Lexical Richness and Its Components | 第16页 |
| ·Previous Studies on Lexical Richness | 第16-21页 |
| ·Previous Studies of Lexical Richness Carried out Abroad | 第16-20页 |
| ·Previous Studies Carried out in China | 第20-21页 |
| ·Measuring Lexical Richness | 第21-31页 |
| ·Measuring Lexical Variation | 第22-24页 |
| ·Measuring Lexical Sophistication | 第24-25页 |
| ·Measuring Lexical Density | 第25-28页 |
| ·Measuring Lexical Error | 第28-31页 |
| Chapter 3 Research Methodology | 第31-36页 |
| ·Construction of the Corpora Used | 第31-32页 |
| ·Material Used in the Study | 第32页 |
| ·Software Packages Used in the Paper | 第32-33页 |
| ·Data Collection and Processing Procedures | 第33-34页 |
| ·Research Questions | 第34页 |
| ·Research Hypotheses | 第34-36页 |
| Chapter 4 Results and Discussion | 第36-57页 |
| ·Results of Lexical Richness and Its Relationship with Writing Quality | 第37-47页 |
| ·Lexical Variation and Its Relationship with Writing Quality | 第37-39页 |
| ·Lexical Sophistication and Its Relationship with Writing Quality | 第39-43页 |
| ·Lexical Density and Its Relationship with Writing Quality | 第43-44页 |
| ·Lexical Error and Its Relationship with Writing Quality | 第44-47页 |
| ·Summary | 第47页 |
| ·Multiple Regression Analysis of Lexical Richness | 第47-50页 |
| ·Interactions among the Four Parameters | 第50-57页 |
| ·Relationship between Lexical Variation and Lexical Sophistication | 第50-51页 |
| ·Relationship between Lexical Variation and Lexical Density | 第51-52页 |
| ·Relationship between Lexical Variation and Lexical Errors | 第52-53页 |
| ·Relationship between Lexical Sophistication and Lexical Density | 第53-54页 |
| ·Relationship between Lexical Sophistication and Lexical Error | 第54-55页 |
| ·Relationship between Lexical Density and Lexical Error | 第55页 |
| ·Summary | 第55-57页 |
| Chapter 5 Conclusions | 第57-63页 |
| ·Major Findings | 第57-59页 |
| ·Implications | 第59-61页 |
| ·Implications for Lexical Teaching | 第59-60页 |
| ·Implications for Lexical Learning | 第60-61页 |
| ·Limitations and Suggestions for Further Studies | 第61-63页 |
| References | 第63-68页 |
| Appendix Ⅰ Error Marking Scheme in CLEC | 第68-70页 |
| Appendix Ⅱ Tagging Scheme for CLEC | 第70-71页 |
| Appendix Ⅲ Sample Compositions in HG and LG | 第71-72页 |
| Acknowledgements | 第72-73页 |
| Resume | 第73-74页 |
