Chapter One Introduction 1.1 Background of the study 1.2 Rationale for the study 1.3 Viewpoint of the study 1.4 Significance of the study 1.5 Organization of the dissertation Chapter Two Literature Review 2.1 Introduction 2.2 Action research 2.2.1 Definition 2.2.2 Significance 2.2.3 Process 2.3 EFL lexical acquisition of undergraduates in China 2.4 Lexicai acquisition strategies 2.5 Strategy training of lexical acquisition 2.6 Lexical testing instruments 2.6.1 Vocabulary breadth testing 2.6.2 Vocabulary depth testing 2.7 Chapter summary Chapter Three Methodology 3.1 Introduction 3.2 An overview of research design 3.2.1 Research cycle 3.2.2 Participants & ethical considerations 3.2.3 Textbook & pedagogy 3.2.4 Procedures for data collection 3.2.5 Methods of data analysis 3.3 Chapter summary Chapter Four Preparation as Stage One 4.1 Introduction 4.2 Confirming a problem & proposing hypotheses 4.3 Making investigations & reconfirming the problem 4.4 Developing an action plan 4.5 Chapter summary Chapter Five Execution as Stage Two 5.1 Introduction 5.2 Pre-testing & post-testing 5.3 Differentiated teaching 5.4 Chapter summary Chapter Six Reflection as Stage Three 6.1 Introduction 6.2 Analyzing data & evaluating effects 6.3 Chapter summary Chapter Seven Suggestions for EFL Teaching Material Development 7.1 Introduction 7.2 An overview 7.3 Lexical input 7.4 Lexical intake 7.5 Lexical output 7.6 Chapter summary Chapter Eight Conclusion 8.1 Summary of the study 8.2 Pedagogical implications 8.3 Limitations of the study 8.4 Suggestions for further studies 8.5 Concluding remarks Bibliography Appendices Appendix One Vocabulary Size Test: Version A Appendix Two Vocabulary Size Test: Version B Appendix Three Vocabulary Size Test: Version C Appendix Four Results of VST (Version A) Appendix Five Results of VST (Version B) Appendix Six Results of VST (Version C) Appendix Seven One student sample of reflective journal Appendix Eight One student sample of VKS testing Appendix Nine Results ofVKS pre-testing (first round) Appendix Ten Results of VKS post-testing (first round) Appendix Eleven Results ofVKS pre-testing (second round) Appendix Twelve Results of VKS post-testing (second round)