Roles of depth of vocabulary knowledge in EFL learner's writing proficiency

Abstract

The principal objective of the study is to examine the association between EFL (English as a foreign language) learners' depth of lexical knowledge and their writing proficiency, and the role that contextual factors play in determining that association. A total of 150 students, 67 from Hong Kong and 83 from mainland China, participated in the study. Nation's Vocabulary Levels Tests (2001), Read's Word Associates Test (1998) and a writing test were the main instruments applied within the study. Measures for assessing lexical richness in learners writing, such as lexical diversity, lexical sophistication and lexical frequency profile, were also deployed within the overall analyses. The cardinal element of the study examines whether EFL learners' depth or extensiveness of vocabulary knowledge is closely related to their writing ability; and whether the depth dimension of word knowledge can provide a distinctive prediction of their writing scores, over and above the contribution made by the breadth of lexical knowledge. In addition to this, the study also explores whether contextual factors affect the association between learners' lexical knowledge and their writing proficiency. Through in-depth investigation, the completed overall study collects both quantitative and qualitative data, originating from two vocabulary tests, a writing test, five case studies, three focus-group interviews, a questionnaire survey and a learner corpus analysis. Amongst other conclusions, the study found 1) that the depth of EFL learners' lexical knowledge provides a unique prediction of their writing scores, over and above the contribution made by the breadth of lexical knowledge ; and 2) that different language learning contexts affect the association between these learners' depth of vocabulary and their writing proficiency. The present study both traverses and fills a gap in the existing literature appertaining to the relationship between EFL learners' depth of word knowledge and their language proficiency. Importantly, the study also draws researchers' attention to the imperative influence of language learning contexts in determining the predictive power of lexical knowledge (in particular the depth of vocabulary knowledge) on learners' writing proficiency. Pedagogically, the study both confirms observations made in previous studies which suggest that the National Matriculation English Test in China cannot objectively measure candidates' writing ability, and reasserts the pressing need for fundamental examination reform in China.