Assessing the Roles of Vocabulary Knowledge in Reading Comprehension [pic]
This study explored the relationships between vocabulary knowledge and reading comprehension in English as a second language (ESL). Using many analyses, the study examined the roles of effects of vocabulary knowledge in assessing the performance of a group of young adult ESL learners with a minimum vocabulary size of 3,000 word families in carrying out reading comprehension tasks. The results support the hypotheses that (1) scores on vocabulary size and reading comprehension are highly, and positively, correlated; and (2) scores on vocabulary knowledge can make a unique contribution to the prediction of reading comprehension levels scores. The outcome of this study will indicate the importance of improving vocabulary knowledge in learners' ESL learning processes.
In first language (L1) research, it has been recognized that vocabulary knowledge makes an important contribution to reading comprehension (Anderson & Freebody, 1981, 1983; Mezynski, 1983; Stratton & Nacke, 1974; Tuinman & Brady, 1974). Second language (L2) research on the relationship between vocabulary and reading is, however, just beginning to gain attention. Within this area, the two ends of the scale are still rather unbalanced: the greater part of the literature has been on how L2 learners acquire their vocabulary through reading, while, except for a very limited number of studies (e.g., de Bot, Paribakht, & Wesche, 1997; Hirsh & Nation, 1992; Laufer, 1989, 1992, 1996), few studies have attempted to determine
The role vocabulary knowledge plays in L2 reading comprehension. Even within the small number of studies that have assessed the relationship between vocabulary knowledge and reading comprehension in L2, the majority focus on breadth of vocabulary knowledge. Little recognition is accorded to the roles other aspects of vocabulary knowledge play. A recognition of depth and breadth as two primary dimensions of vocabulary knowledge is essential to understanding the relationship between vocabulary knowledge and reading comprehension (Qian, 1998). To map out a conceptual framework for the present study, it is necessary to clarify what we mean by `breadth' and `depth' of vocabulary knowledge. In the present study, breadth of vocabulary knowledge is defined as vocabulary size, or the number of words for which a learner has at least some minimum knowledge of meaning. Depth of vocabulary knowledge is defined as a learner's level of knowledge of various aspects of a given word, or how well the learner knows this word. Over the years, researchers such as Cronbach (1942), Dale (1965), Henriksen (1999), Nation (1990), and Richards (1976) have proposed varying, but generally complementary, conceptual frameworks of vocabulary knowledge. However, produced in different contexts, these frameworks do not provide an explicit description of what composes the mass of vocabulary knowledge in the context of distinguishing depth from breadth. In order to provide a theoretical framework for the present study, a working definition of depth of vocabulary knowledge is proposed below. This framework takes into account the merits of previous frameworks, particularly the definitions by Nation (1990) and Richards (1976). The framework identifies various important aspects composing depth of vocabulary knowledge for reading, especially from the perspective of their possible contribution to reading comprehension processes:
1. Pronunciation and spelling: how different forms of the word are pronounced and spelled;
2. Morphological properties: the word's stem, its capability of inflection, derivation, and other word formation devices, and its possible parts of speech;
3. Syntactic properties:...