| ACKNOWLEDGEMENTS | 第1-5页 |
| ABSTRACT | 第5-7页 |
| 摘要 | 第7-9页 |
| LIST OF FIGURES AND TABLES | 第9-10页 |
| ABBREVIATIONS | 第10-13页 |
| Chapter One INTRODUCTION | 第13-16页 |
| Chapter Two LITERATURE REVIEW | 第16-37页 |
| ·Corpus:Its Past and Present | 第16-24页 |
| ·Definition of corpus | 第16-17页 |
| ·Historical development of corpus | 第17-21页 |
| ·Application of corpus | 第21-22页 |
| ·Studies based on corpus in China | 第22-24页 |
| ·Limitations of current studies | 第24页 |
| ·The Relationship of Lexical Proficiency and Quality of Writing | 第24-37页 |
| ·Lexical proficiency | 第24-27页 |
| ·Quality of writing | 第27页 |
| ·The relationship between lexical proficiency and quality of writing:home and abroad | 第27-34页 |
| ·Limitations of previous studies | 第34-35页 |
| ·An overview of the present study | 第35-37页 |
| Chapter Three RESEARCH METHODS AND DESIGN | 第37-42页 |
| ·Research Questions | 第37页 |
| ·Materials of Research | 第37页 |
| ·Scoring Principles of CET 4 and 6 | 第37-38页 |
| ·Dependent Variables and Independent Variables | 第38页 |
| ·Research Process | 第38-40页 |
| ·A research Sample | 第40-42页 |
| Chapter Four THE RESULTS | 第42-57页 |
| ·Descriptive Statistics | 第42-45页 |
| ·Descriptive statistics of all compositions | 第42-43页 |
| ·Descriptive statistics of CET 4 compositions | 第43-44页 |
| ·Descriptive statistics of CET 6 compositions | 第44页 |
| ·Comparison of descriptive statistics between CET 4 and CET 6 | 第44-45页 |
| ·Comparison of Lexical Features across Different Qualities of Compositions | 第45-55页 |
| ·CET 4 compositions | 第46-51页 |
| ·CET 6 compositions | 第51-55页 |
| ·Correlation Analysis | 第55-57页 |
| Chapter Five DISCUSSION | 第57-73页 |
| ·General Lexical Features of CET 4 and 6 Compositions | 第57-60页 |
| ·Developmental Features of Productive Vocabulary Reflected in CET4 and CET 6 Compositions | 第60-61页 |
| ·The Impact of Proficiency of Productive Vocabulary on CET 4 and CET 6 Compositions | 第61-71页 |
| ·The relationship between text length and the quality of writing | 第61-63页 |
| ·The relationship between lexical richness and the quality of writing | 第63-69页 |
| ·The relationship between misspellings and the quality of writing | 第69页 |
| ·The relationship between lexical diversity and the quality of writing | 第69-70页 |
| ·The impact of other possible factors on the quality of writing | 第70-71页 |
| ·Limitations of This Research | 第71页 |
| ·Suggestions for English Writing Instruction | 第71-73页 |
| Chapter Six CONCLUSION | 第73-76页 |
| Bibliography | 第76-80页 |
