Chapter 1 Introduction 1．1 The research context 1．2 Rationale for the present research 1．3 The general research purpose 1．4 The overall structure of the book Chapter 2 Literature Review 2．1 Introduction 2．2 Input and interaction in SLA 2．2．1 Early research on accommodative features of L2 input and interaction 2．2．2 Different views on the role of input and interaction in SLA 2．2．3 The development of the interactionist view on input and interaction in SLA 2．3 Accommodation Theory 2．3．1 The development of Accommodation Theory 2．3．2 The studies of accommodation from different aspects 2．3．3 The studies of accommodation in oral proficiency interviews 2．3．4 Lexical accommodation in oral examinations 2．4 Vocabulary assessment and lexical richness 2．4．1 The important role of vocabulary in L 2．4．2 The definition of word 2．4．3 Different dimensions of vocabulary knowledge 2．4．4 Dimensions of vocabulary assessment 2．4．5 Lexical richness 2．5 The gap in literature and research questions Chapter 3 The Pilot Study 3．1 Introduction to the pilot study 3．2 Research design of the pilot study 3．2．1 Research questions 3．2．2 Subjects 3．2．3 Instruments 3．2．4 Data collection and procedures 3．3 Analyses and results 3．3．1 Analyses and results of the questionnaires 3．3．2 Results of the quantitative measures 3．4 Discussion Chapter 4 Research Methodology of the Main Study 4．1 Refined Research Questions 4．2 Subjects 4．2．1 The candidates 4．2．2 The examiners 4．3 Instruments 4．3．1 The Corpus of 2008 GESE Examinations 4．3．2 The introduction of GESE in Beijing， China 4．3．3 The Assessment of GESE 4．3．4 Lexical richness measures 4．3．5 Quantitative analysis 4．3．6 Qualitative analysis 4．4 Procedures 4．4．1 Data collection procedures 4．4．2 Data transcription 4．4．3 Analyses of the quantitative variables 4．4．4 Qualitative analysis 4．5 Summary Chapter 5 Results of the Quantitative Analyses 5．1 The candidate （student/examinee） variables 5．1．1 Lexical measures of the candidates of three different grades 5．1．2 Different measures of good performers and poor performers at the same stage 5．1．3 The relationship among the candidate variables 5．1．4 Summary 5．2 Analyses of examiner / teacher variables 5．2．1 The teacher/examiner lexical variables of three different grades 5．2．2 The examiner lexical variables for qualified and poor performers 5．3 Summary Chapter 6 The Qualitative Analyses 6．1 The participants 6．2 Data collection and procedures 6．3 Coding and analyses of the qualitative research data 6．4 Results of the research on the first theme： factors that affect rating of GESE 6．4．1 Intuition vs． analytical assessment based on assessment criteria 6．4．2 Assessment of vocabulary 6．5 Factors contributing to Grade 7 candidates' poor performance 6．5．1 The motivation of taking Grade 7 GESE 6．5．2 The difficulty of the Interactive Phase for the candidates of Grade 6．5．3 The improper training 6．5．4 Cultural factors in the educational setting 6．6 The consistency of the rating 6．7 Summary Chapter 7 Conclusion 7．1 Summary of the quantitative results 7．1．1 Summary of the results of the first three research questions 7．1．2 Summary of the results of the research questions 4 7．2 Summary of the qualitative results 7．3 Implications of the present research 7．4 Limitations of the present research & future directions References Appendixes Appendix 1 The questionnaire of the pilot study Appendix 2 The CHAT format of the transcription Appendix 3 The output of the morpost command on the transcription Appendix 4 The CLAN results of MLU of both the examiner and the candidate Appendix 5 The CLAN result of VOCD of the candidate Appendix 6 The CLAN result of VOCD of the examiner Appendix 7 SPSS output of the comparions of candidate Type Appendix 8 The interview outline for the qualitative research