Introducing the Study 1
0.1 Introduction 1
0.2 The Need for the Study 3
0.2.1 The Theoretical Need 3
0.2.2 The Methodological Need 5
0.2.3 The Pedagogical Need 6
0.3 Significance of the Study 8
0.3.1 Theoretical Significance 8
0.3.2 Methodological Significance 9
0.3.3 Pedagogical Significance 10
0.4 Outline of the Study 11
0.5 Summary 12
PART Ⅰ BACKGROUND 16
Chapter Ⅰ Literature Review 16
1.1 Introduction 16
1.2 The Trait and Interactionalist Approaches to Assessing L2 Vocabulary 16
1.2.1 The Trait Approach to Assessing Vocabulary 17
1.2.2 The Interactionalist Approach to Assessing Vocabulary 19
1.3 The Trait and Interactionalist Approaches:A Contrast 20
1.4 Previous Measures of L2 Lexical Performance 24
1.4.1 Lexical Variance 24
1.4.2 Lexical Density 26
1.4.3 Lexical Sophistication 27
1.4.4 Lexical Originality 29
1.4.5 Collocation 31
1.5 Previous Studies of the Relationship Between L2 Lexical Performance Measures and L2 Writing Quality 34
1.5.1 Relationship Between Lexical Variance Measures and L2 Writing Quality 35
1.5.2 Relationship Between Lexical Density Measures and L2 Writing Quality 37
1.5.3 Relationship Between Lexical Sophistication Measures and L2 Writing Quality 39
1.5.4 Relationship Between Lexical Originality Measures and L2 Writing Quality 40
1.5.5 Relationship Between Collocation and L2 Writing Quality 41
1.6 Problems in the Previous Studies of L2 Lexical Performance Measures 44
1.6.1 Lack of a General Framework in the L2 Lexical Performance Measures 44
1.6.2 Confusing Definitions of L2 Lexical Performance Measures 45
1.6.3 Unclear Procedures for Most L2 Lexical Performance Measures 46
1.6.4 Problems in Examining the Relationship Between L2 Lexical PerformanceMeasures and L2 Writing Quality 47
1.7 Solutions to the Problems 52
1.7.1 Establishing a General Model of L2 Lexical Performance 52
1.7.1.1 Lexical Richness 53
1.7.1.2 Collocation 56
1.7.1.3 Conceptual Model of L2 Lexical Performance as Represented by Lexical Richness and Collocation 61
1.7.2 Proper Measurements of the Components of Lexical Richness and Collocation 65
1.7.3 Using Analytic Scoring 71
1.7.4 LISREL Modeling 73
PART Ⅱ METHODOLOGY 76
Chapter Ⅱ Research Design 76
2.1 Introduction 76
2.2 Research Questions 76
2.3 Materials 79
2.4 Research Tools 80
2.4.1 The LISREL 81
2.4.2 Range 12 83
2.4.3 WordSmith Tools 84
2.4.4 Cobuild Collocation Sampler 88
2.4.4.1 A Concise Introduction to Cobuild Collocation Sampler 88
2.4.4.2 Rational for MI Score and T-Score 89
2.4.5 The British National Corpus 93
Chapter Ⅲ Statistical Procedures 94
3.1 Introduction 94
3.2 Statistical Procedures of Measuring L2 Lexical Performance Variables 94
3.2.1 Procedures for Variables of Lexical Richness 94
3.2.1.1 Procedure for Lexical Variance 95
3.2.1.2 Procedure for Lexical Density 97
3.2.1.3 Procedure for Lexical Sophistication 97
3.2.1.4 Procedure for Lexical Originality 100
3.2.2 Procedures for Variables of Collocation 102
3.2.2.1 Identifying Lexical and Grammatical Collocations 103
3.2.2.2 Identifying Idioms 106
3.2.2.3 Counting Lexical,Grammatical Collocations,and Idioms 107
3.3 Scoring L2 Compositions 107
PART Ⅲ RESULTS AND DISCUSSION 112
Chapter Ⅳ Measurement and Structural Models 112
4.1 Introduction 112
4.2 A Review of the Research Questions 112
4.3 General Model of L2 Lexical Performance Represented by Lexical Richness and Collocation 113
4.3.1 Description of the Observed Variables of Lexical Richness and Collocation 113
4.3.2 Description of the General Model of L2 Lexical Performance 114
4.3.3 Interpreting the General Model of L2 Lexical Performance 116
4.3.3.1 Measurement Model of Lexical Richness 116
4.3.3.2 Measurement Model of Collocation 117
4.3.3.3 Conceptual Model of L2 Lexical Performance 120
4.4 Structural Models of L2 Lexical Performance and L2 Writing Quality 121
4.4.1 Description of the Structural Models 121
4.4.1.1 Model 1 Relationship Between L2 Lexical Performance and the Total L2 Writing Quality 122
4.4.1.2 Model 2 Relationship Between L2 Lexical Performance and the Partial L2 Writing Quality 124
4.4.2 Interpreting the Structural Models 126
4.4.2.1 Interpreting Model 1 126
4.4.2.1.1 Direct Effect of Lexical Richness on L2 Writing Quality 126
4.4.2.1.2 Direct Effect of Collocation on L2 Writing Quality 139
4.4.2.1.3 Indirect Effect of Lexical Richness on L2 Writing Quality 144
4.4.2.1.4 Effect of L2 Lexical Performance on L2 Writing Quality 145
4.4.2.2 Interpreting Model 2 152
4.5 Summary 153
Chapter Ⅴ A Comparison of Collocations Between the Low and High Achiever Groups 155
5.1 Introduction 155
5.2 Research Question 156
5.3 Selection of the Low and High Achiever Groups 157
5.4 Lexical Collocations Between the Low and High Achiever Groups:A Comparison 158
5.4.1 Definition of an Advanced Lexical Collocation 158
5.4.2 Description of the Overall Lexical Collocations 159
5.4.3 Description of Lexical Collocations at Different Word Frequency Levels 160
5.4.4 No Inter-group Difference in the Use of Lexical Collocations:An Explanation 161
5.4.4.1 Limited Choice of Different Collocates of the Same Lexical Words 162
5.4.4.2 Ignorance of Collocational Constraints 168
5.4.4.3 Slow Progress in the Acquisition of Advanced Lexical Collocations 177
5.5 Grammatical Collocations Between the Low and High Achiever Groups:A Comparison 182
5.5.1 Definition of an Advanced Grammatical Collocation 182
5.5.2 Description of the Overall Grammatical Collocations 183
5.5.3 Description of Grammatical Collocations at Different Word Frequency Levels 184
5.5.4 Significant Inter-group Difference in the Use of Grammatical Collocations:An Explanation 185
5.5.4.1 Grammatical Knowledge 186
5.5.4.2 A Fairly Strong Sense of Grammatical Collocations 189
5.5.4.3 Productive Vocabulary Size and Morphology 195
5.6 Summary 197
PART Ⅳ CONCLUSION 200
Chapter Ⅵ L2 Lexieal Performance and L2 Writing Quality:Conclusion 200
6.1 Introduction 200
6.2 A Summary of the Major Findings 201
6.2.1 Framework of L2 Lexical Performance 201
6.2.2 Effects of L2 Lexical Performance on L2 Writing Quality 201
6.2.3 Differences in the Use of Collocations Between the Low and High Achiever Groups 202
6.3 Theoretical Significance 203
6.3.1 Construct of L2 Lexical Performance 204
6.3.2 Modeling the Relationship Between L2 Lexical Performance and L2 Writing Quality 204
6.4 Methodological Significance 205
6.5 Pedagogical Significance 206
6.6 Limitations of the Study 211
6.7 Directions for Future Research 212
References 214
Appendices 229