| Acknowledgements | 第6-7页 |
| 摘要 | 第7-9页 |
| Abstract | 第9-10页 |
| Contents | 第11-14页 |
| List of Abbreviations | 第14-15页 |
| List of Tables | 第15-16页 |
| List of Figures | 第16-17页 |
| Chapter One Introduction | 第17-22页 |
| 1.1 Background of the Study | 第17-18页 |
| 1.2 Purpose of the Study | 第18页 |
| 1.3 Significance of the Study | 第18-20页 |
| 1.4 Organization of the Thesis | 第20-22页 |
| Chapter Two Literature Review | 第22-39页 |
| 2.1 Assessment of L2 Vocabulary | 第22-25页 |
| 2.1.1 The Trait and Interactional Approaches to Assessing L2 Vocabulary | 第22-23页 |
| 2.1.2 Assessment of L2 Lexical Performance | 第23-25页 |
| 2.2 Previous Measures of L2 Lexical Performance in L2 Writing | 第25-31页 |
| 2.2.1 Definitions and Evaluations of Lexical Richness | 第25-27页 |
| 2.2.2 Measures for Lexical Richness | 第27-30页 |
| 2.2.2.1 Lexical Variation | 第27-28页 |
| 2.2.2.2 Lexical Density | 第28页 |
| 2.2.2.3 Lexical Sophistication | 第28-30页 |
| 2.2.3 Measures for Collocation | 第30-31页 |
| 2.3 A Developmental Perspective of Vocabulary in L2 Writing | 第31-34页 |
| 2.4 Previous Studies on the Relationship between L2 Lexical Performance Measures and L2 Writing Quality | 第34-38页 |
| 2.4.1 Relationship between Lexical Richness and L2 Writing Quality | 第34-36页 |
| 2.4.2 Relationship between Collocation and L2 Writing Quality | 第36-38页 |
| 2.5 Summary | 第38-39页 |
| Chapter Three Methodology | 第39-50页 |
| 3.1 Research Questions | 第39页 |
| 3.2 Participants | 第39-40页 |
| 3.3 Procedures of Data Collection | 第40-43页 |
| 3.3.1 Implementing Writing Tasks | 第40-41页 |
| 3.3.2 Data Selection and Sampling | 第41-42页 |
| 3.3.3 Composition Evaluation | 第42-43页 |
| 3.4 Construction of the DIY Corpus | 第43-44页 |
| 3.4.1 Data Documentation and Modification | 第43-44页 |
| 3.4.2 POS Tagging of the Corpus | 第44页 |
| 3.5 Data Analysis | 第44-50页 |
| 3.5.1 Corpus Tools Used | 第44-46页 |
| 3.5.2 Statistical Procedures of Measuring L2 Lexical Performance | 第46-49页 |
| 3.5.2.1 Measuring of Lexical Variation | 第46页 |
| 3.5.2.2 Measuring of Lexical Density | 第46页 |
| 3.5.2.3 Measuring of Lexical Sophistication | 第46-47页 |
| 3.5.2.4 Measuring of the Variables of Collocation | 第47-49页 |
| 3.5.3 Statistical Treatment of the Data | 第49-50页 |
| Chapter Four Developmental Features of Lexical Performance in L2 Writing | 第50-65页 |
| 4.1 Developmental Features of Lexical Richness | 第50-58页 |
| 4.1.1 Development of Lexical Variation | 第50-53页 |
| 4.1.1.1 Description of Lexical Variation at Different Grade Levels | 第50-52页 |
| 4.1.1.2 Discussion on the Developmental Features of Lexical Variation | 第52-53页 |
| 4.1.2 Development of Lexical Density | 第53-54页 |
| 4.1.2.1 Description of Lexical Density at Different Grade Levels | 第53-54页 |
| 4.1.2.2 Discussion on the Developmental Features of Lexical Density | 第54页 |
| 4.1.3 Development of Lexical Sophistication | 第54-58页 |
| 4.1.3.1 Description of Sophistication at Different Grade Levels | 第54-57页 |
| 4.1.3.2 Discussion on the Developmental Features of Lexical Sophistication | 第57-58页 |
| 4.2 Developmental Features of Collocation | 第58-65页 |
| 4.2.1 Overall Description of the Three Types of Collocation | 第58-62页 |
| 4.2.2 Discussion on the Developmental Features of the Three Types of Collocation | 第62-65页 |
| 4.2.2.1 Developmental Features of Lexical and Grammatical Collocations | 第62-63页 |
| 4.2.2.2 Developmental Features of Idioms | 第63-65页 |
| Chapter Five Relationship between Lexical Performance and L2 WritingPerformance | 第65-91页 |
| 5.1 Two-directional Comparisons of Overall L2 Writing Performance | 第65-69页 |
| 5.1.1 L2 Writing Performance at Different Grade Levels | 第65-68页 |
| 5.1.2 Representing L2 Writing Performance at Different Proficiencey Levels | 第68-69页 |
| 5.2 Relationship between Lexical Richness and L2 Writing Performance | 第69-77页 |
| 5.2.1 Lexical Variation at Different Writing Proficiency Levels | 第69-71页 |
| 5.2.2 Lexical Density at Different Writing Proficiency Levels | 第71-73页 |
| 5.2.3 Lexical Sophistication at Different Writing Proficiency Levels | 第73-77页 |
| 5.3 Relationship between Collocation and Overall Writing Performance | 第77-91页 |
| 5.3.1 Overall Description of Collocation at Different Writing Proficiency Levels | 第77-80页 |
| 5.3.2 Lexical Collocation and L2 Writing Performance | 第80-85页 |
| 5.3.3 Grammatical Collocation and L2 Writing Performance | 第85-88页 |
| 5.3.4 Idiom and L2 Writing Performance | 第88-91页 |
| Chapter Six Conclusions | 第91-98页 |
| 6.1 Summary of Major Findings | 第91-93页 |
| 6.2 Pedagogical Implications of the Study | 第93-96页 |
| 6.3 Limitations of the Study | 第96-97页 |
| 6.4 Suggestions for Further Studies | 第97-98页 |
| References | 第98-102页 |
| Appendix | 第102-104页 |
| Appendix Ⅰ | 第102-103页 |
| Appendix Ⅱ | 第103-104页 |
| Appendix Ⅲ | 第104页 |
