Productive Vocabulary Size Test as a Predictor of L2 Learners' Success in Academic Writing Skill

In this study an attempt has been made to investigate if vocabulary tests may predict L2 learners’ writing score in IELTS. 131 postgraduate international students studying in Universiti Teknologi Malaysia (UTM) who obtained the minimum score (i.e. 6) in IELTS as a requirement for enrollment were participants of this study. Two vocabulary size tests (PVLT & Lex30) together with a test of vocabulary depth (WAT) were given to participants. Then, participants’ scores from three tests were correlated with their score in the writing section of IELTS. The results of the study revealed significant correlation coefficients between productive vocabulary size and academic writing skills. Moreover, the findings of Multiple Regression indicated that productive vocabulary levels test (PVLT) could be possibly a good predictor for IELTS academic writing. Further, scatter plots revealed a possible threshold of 2000 words for a L2 learner to get 7 in IELTS academic writing. The findings drawn from the study enable teachers to predict their learners’ competency in writing skill by through various vocabulary tests.