| Acknowledgements | 第1-6页 |
| Abstract | 第6-8页 |
| 摘要 | 第8-9页 |
| Contents | 第9-11页 |
| Chapter One Introduction | 第11-16页 |
| ·Background and Significance of the Study | 第11-13页 |
| ·Objectives of the Present Study | 第13-14页 |
| ·Organization of the Thesis | 第14-16页 |
| Chapter Two Literature Review | 第16-34页 |
| ·Vagueness | 第16-19页 |
| ·Pragmatic Vagueness | 第19-23页 |
| ·Definition of Pragmatic Vagueness | 第19-21页 |
| ·Classification of Vagueness in Pragmatics | 第21-23页 |
| ·Development of Vagueness Research | 第23-27页 |
| ·Relevant Research of Vagueness Abroad | 第23-25页 |
| ·Relevant Research of Vagueness at Home | 第25-27页 |
| ·Development of Pragmatic Vagueness Research | 第27-30页 |
| ·Relevant Research of Pragmatic Vagueness Abroad | 第27-28页 |
| ·Relevant Research of Pragmatic Vagueness at Home | 第28-30页 |
| ·A Review of Relevance Theory | 第30-34页 |
| ·Relevant Research of Relevance Abroad | 第30-31页 |
| ·Relevant Research of Relevance at Home | 第31-34页 |
| Chapter Three Key Concepts of Relevance Theory | 第34-42页 |
| ·Definition of Relevance | 第34-35页 |
| ·Degree of Relevance: Contextual Effects and Processing Efforts | 第35-36页 |
| ·Principle of Relevance | 第36-38页 |
| ·Cognitive Environment | 第38-40页 |
| ·Ostensive-Inferential Communication | 第40-42页 |
| Chapter Four A Case Study of Obama’s Weekly Radio Addresses | 第42-77页 |
| ·Research Questions | 第42页 |
| ·Research Method | 第42-43页 |
| ·Data Collection | 第43-44页 |
| ·Data Analysis | 第44-77页 |
| ·Relevance-theoretic Analysis of Pragmatic Vagueness | 第45-69页 |
| ·Relevance-theoretic Analysis of Fuzzy Continuum | 第48-49页 |
| ·Relevance-theoretic Analysis of Taxonomic Category | 第49-51页 |
| ·Relevance-theoretic Analysis of Nomenclative Evaluation | 第51-62页 |
| ·Relevance-theoretic Analysis of Hedging in Discourses | 第62-69页 |
| ·Linguistic Realization of Pragmatic Vagueness | 第69-73页 |
| ·Linguistic Manipulation at Lexical Level | 第69-70页 |
| ·Linguistic Manipulation at Syntactical Level | 第70-72页 |
| ·Linguistic Manipulation at Discourse Level | 第72-73页 |
| ·Functions of Pragmatic Vagueness in Weekly Radio Addresses | 第73-77页 |
| ·Enhancing the Reliability and Appropriateness | 第73-74页 |
| ·Achieving Politeness and Euphemism | 第74-75页 |
| ·Minimizing the Negative Effects | 第75-77页 |
| Chapter Five Conclusion | 第77-80页 |
| ·Major Findings of the Study | 第77-78页 |
| ·Limitations and Suggestions for Further Research | 第78-80页 |
| Bibliography | 第80-84页 |
| Published Papers | 第84-85页 |
| Appendix | 第85-109页 |
