The Contribution of Breadth and Depth of Vocabulary Knowledge to EFL Learners’ Summary Writing Success

The aim of the present study was to investigate the relationship between breadth and depth of vocabulary knowledge and EFL learners’ success in summary writing. In this study, a sample of 80 upper intermediate students majoring in English translation were assessed by their English proficiency level, writing proficiency and their English vocabulary knowledge; then, they summarized an argumentative, a narrative and an expository text. The results of correlation analysis showed that while both breadth and depth of vocabulary knowledge are significantly related to identification of main ideas, use of summarizing strategies and proper writing indices in the so-called texts summaries, the contribution of depth of vocabulary knowledge to summary writing is meaningfully stronger, than the effect of its size. Similarly, the regression analysis showed that depth of vocabulary knowledge is a better predictor than the breadth, in determining students’ summary writing success. Based on the findings, language teachers are encouraged to put more emphasis on depth of vocabulary knowledge of learners and familiarize them with summarizing rules.