Assessing Chinese English Learners' Vocabulary Knowledge And Its Role In Reading Comprehension

Vocabulary testing is a very important topic in the studies of second language acquisition (SLA), and the assessment of the relationship between vocabulary knowledge and reading comprehension is becoming an increasingly important research interest. Researchers have already carried out some innovative studies and gained some important insights in this area. However, due to the limitations of testing theory and instruments, questions concerning the relationship between vocabulary knowledge and reading comprehension remain to be studied in more details. This is especially true in the Chinese SLA context.The present study has aimed to assess the receptive vocabulary knowledge of Chinese intermediate level ESL learners from two dimensions: breadth and depth, and to probe into the role of vocabulary knowledge in reading comprehension. Vocabulary breadth, in this study, refers to the quantity of a learner's receptive vocabulary or the number of words that a learner has at least some minimum knowledge of. Depth of vocabulary knowledge (DVK) is the quality of a learners'vocabulary knowledge, including six aspects of knowing a word: 1) pronunciation and spelling, 2) morphological properties, 3) syntactic properties, 4) meaning, 5) register and 6) frequency.The breadth and depth of learners'vocabulary knowledge were measured by the Vocabulary Levels Test (VLT) and the Word Association Test (WAT) respectively. The WAT measures learners'DVK by tapping their word association knowledge, involving two most important aspects of DVK, i.e., lexical meaning and collocation. Learners'reading proficiency was inferred from two recent classroom examinations.The specific research questions that the study attempts to address are:(1) How does learners'vocabulary breadth correlate with their vocabulary depth?(2) How does word frequency affect learners'depth of vocabulary knowledge?(3) How do breadth and depth of vocabulary knowledge influence reading comprehension respectively?(4) To what extent do the scores on vocabulary breadth and depth contribute to the prediction of learners'reading proficiency? On the basis of the empirical studies, we have drawn the following conclusions:(1) Learners'vocabulary breadth significantly correlates with their vocabulary depth.(2) The word frequency exerts a significant impact on learners'depth of word knowledge; that is, the more frequent a word is, the better learners'knowledge of the word is.(3) Both vocabulary breadth and vocabulary depth have a significant influence on reading comprehension.(4) Both breadth and depth of vocabulary knowledge can predict reading proficiency to a significant extent, with the latter as a stronger predictor. The insufficiency of breadth and depth of vocabulary knowledge can restrain or"short circuit"learners'reading comprehension ability.The research has both theoretical and practical significance. On the basis of our framework of depth of vocabulary knowledge, we designed a testing instrument of vocabulary depth, i.e., WAT, and verified its reliability and validity by empirical studies. Secondly, in our assessment of the vocabulary knowledge of Chinese ESL learners, we not only evaluated the relationship between vocabulary breadth and depth, but also investigated the impact of word frequency on depth of vocabulary knowledge. Therefore, we gained some valuable insights into the depth dimension of vocabulary knowledge. Thirdly, we effectively assessed the role of vocabulary knowledge in reading comprehension. We found that vocabulary depth was at least as important to reading comprehension as vocabulary breadth. And finally, our study shed some light on the instruction of vocabulary and reading. We believe that our tests, by further promotion, could have positive effects on students'vocabulary acquisition and improvement of reading comprehension ability.