Contents -- Thanks and Acknowledgements 9 -- 1. Introduction 11 -- 1.1 Background and Purpose of this Study 11 -- 1.2 The Theoretical and Methodological Framework 13 -- 1.3 Outline of Content 21 -- 2. A Corpus of Reading Comprehension Tests 23 -- 2.1 The DIALANG Sub-corpus 24 -- 2.2 The TOEFL Sub-corpus 26 -- 2.3 The IELTS Sub-corpus 30 -- 2.4 The PET Sub-corpus 32 -- 2.5 The FCE Sub-corpus 34 -- 2.6 The CAE Sub-corpus 36 -- 3. Quantitative Investigation into the Complexity of the Texts of the Corpus 41 -- 3.1 The Type/Token Ratio 42 -- 3.2 Measuring Lexical Density and Lexical Variation 48 -- 3.2.1 Measures of Lexical Density 49 -- 3.2.1.1 Lexical Items vs. Grammatical Words 53 -- 3.2.1.2 Lexical Density (Ure's method) in the Corpus 58 -- 3.2.2 A Measure of Lexical Variation 64 -- 3.3 Measuring Vocabulary Difficulty 71 -- 3.3.1 Range 32 and the Underlying Research 72 -- 3.3.2 Using Range 32 and Base Word Lists for the Analysis of the Corpus 75 -- 3.4 Measuring Grammatical Intricacy and Halliday's method of Measuring Lexical Density 87 -- 3.4.1 Halliday's Method of Calculating Lexical Density (LDH), Grammatical Intricacy, the Grammar of the Clause Complex, and Embedding 88 -- 3.4.1.1 The Clause Complex 89 -- 3.4.1.2 Embedding of Clauses 94 -- 3.4.2 Further Investigation of the Lexical Density of the Texts and an Investigation of their Grammatical Intricacy 97 -- 3.5 Measuring Readability 103 -- 3.5.1 Readability Formulae 103 -- 3.5.2 Investigating the Readability of the Corpus 106 -- 3.6 On the Relationship between the Variables 113 -- 4. Text Complexity, Participant Identification and Cohesion in the Corpus 123 -- 4.1 Participant Identification in English: from Discourse Semantics to Lexicogrammar 124 -- 4.1.1 Participant Identification in English: a Review of some Relevant Contributions 124 -- 4.1.2 Phoricity and the Tracking System Network 129.

4.1.3 The Participant Identification System Network 140 -- 4.2 Semantics, Lexicogrammar and the Textual Metafunction: a Systemic Functional Perspective 147 -- 4.2.1 The Semantic and the Lexicogrammatical Strata in Systemic Functional Linguistics 148 -- 4.2.2 The Textual Metafunction: Cohesion and Thematic Structure in English 150 -- 4.2.2.1 Cohesion in English 151 -- 4.2.2.2 Thematic Structure 153 -- 4.3 Participant Identification and the English Nominal Group 157 -- 4.4 The Role of Participant Identification and of Textual Cohesion in the Corpus 164 -- 4.4.1 Test 12 165 -- 4.4.2 Tests 2, 25 and 11 170 -- 4.4.2.1 Test 2 171 -- 4.4.2.2 Test 25 174 -- 4.4.2.3 Test 11 181 -- 4.4.3 Test 14 184 -- 4.4.4 Test 22 189 -- 4.4.5 Tests 15, 3 and 13 193 -- 4.4.5.1 Test 15 194 -- 4.4.5.2 Test 3 202 -- 4.4.5.3 Test 13 203 -- 4.4.6 Tests 18, 19, 23, and 21 206 -- 4.4.6.1 Tests 18 and 19 206 -- 4.4.6.2 Tests 23 and 24 207 -- 5. Assessing Test Difficulty: Data Analysis of Tests and Feedback Questionnaires 211 -- 5.1 Setting the Scene for this Part of the Study 211 -- 5.2 Reliability and Validity in Language Testing 213 -- 5.3 Test and Questionnaire Administration and Data Analysis 216 -- 5.4 Test Battery 1 (from Test 01 to Test 10) 222 -- 5.5 Test Battery 2 (from Test 18 to Test 21) 240 -- 5.6 Test Battery 3 (Tests 11, 12, 22, and 23) 251 -- 5.7 Test Battery 4 (from Test 12 to Test 16) 260 -- 5.7.1 From Test 13 to Test 16 262 -- 5.7.2 Test 12 and the Perception of the Difficulty of the Tests in Battery 4 271 -- 5.8 Test Battery 5 (Tests 17, 24 and 25) 278 -- 5.9 Relationship between Test Takers' Performance, their Perception of Text/Task Difficulty and Results of the Quantitative Investigation 289 -- 6. Conclusions 295 -- References 309 -- Appendix 321 -- Index 351.