| ABSTRACT | 第1-6页 |
| 摘要 | 第6-10页 |
| LIST OF TABLES | 第10-11页 |
| LIST OF FIGURES | 第11-12页 |
| Chapter One INTRODUCTION | 第12-16页 |
| ·Background of the Present Study | 第12-14页 |
| ·Significance of the Research | 第14-15页 |
| ·Originality of the Study | 第15页 |
| ·Organization of the Research Paper | 第15-16页 |
| Chapter Two LITERATURE REVIEW | 第16-32页 |
| ·AES Studies Abroad | 第16-27页 |
| ·Development of AES Systems | 第16-18页 |
| ·Major AES Systems | 第18-22页 |
| ·Strengths and Weaknesses of AES | 第22-24页 |
| ·Validity of AES Systems | 第24-27页 |
| ·Domestic Studies on AES | 第27-31页 |
| ·Introduction of Foreign AES Systems | 第27页 |
| ·Development of Domestic AES Systems | 第27-28页 |
| ·Application of AES Systems | 第28-29页 |
| ·Major Domestic AES Systems | 第29-30页 |
| ·Validity of Domestic AES Systems | 第30-31页 |
| ·Summary | 第31-32页 |
| Chapter Three METHODOLOGY | 第32-45页 |
| ·Research Questions | 第32页 |
| ·Subject of the Present Study | 第32-34页 |
| ·Sampling of the Present Study | 第34-35页 |
| ·Data Collection and Analysis Procedures | 第35-36页 |
| ·Related Tools | 第36-37页 |
| ·VocabProfilers | 第36页 |
| ·L2 Syntactic Complexity Analyzer | 第36-37页 |
| ·Coh-Metrix 3.0 | 第37页 |
| ·Variables | 第37-44页 |
| ·Dependent Variables | 第37-38页 |
| ·Independent Variables | 第38-44页 |
| ·Data analysis | 第44-45页 |
| Chapter Four DATA ANALYSIS AND RESULTS | 第45-53页 |
| ·Comparison of Scores from Two Scoring Methods | 第45-46页 |
| ·Comparison of Mean Scores by Pigai and Human | 第45页 |
| ·Agreement of Two Scoring Methods | 第45-46页 |
| ·Correlation Analysis between Pigai Scores and Human Scores | 第46页 |
| ·The Impact of Essay Quality on the Validity of Pigai | 第46-48页 |
| ·Correlation between Essay Quality and Score Difference | 第46-47页 |
| ·Distribution of Score Difference across Different Qualities of Essays | 第47-48页 |
| ·Impacts of Quantitative Features on Human & Machine Scores | 第48-53页 |
| ·Regression Models of the CET-4 Essay Scores | 第48-50页 |
| ·Regression Models of the CET-6 Essay Scores | 第50-53页 |
| Chapter Five DISCUSSION | 第53-62页 |
| ·Validity Difference between Pigai and Foreign AES Systems and Possible Causes | 第53-56页 |
| ·The General Picture of the Validity of Pigai | 第53-54页 |
| ·Causes of the Validity Difference between Pigai and Foreign AES Systems | 第54-56页 |
| ·Analysis of the Misjudgment of High Quality Essays | 第56-58页 |
| ·Impacts of Quantitative Features on Pigai and Human Scores | 第58-62页 |
| Chapter Six CONCLUSION | 第62-66页 |
| ·Major Findings | 第62-63页 |
| ·Implications of the Study | 第63-64页 |
| ·Limitations and Directions for Future Studies | 第64-66页 |
| REFERENCES | 第66-71页 |
| ABBREVIATIONS | 第71-73页 |
| ACKNOWLEDGEMENTS | 第73页 |
