Maryam Noshadi
Mohsen Mobarki

The present study intended to examine the role of depth versus breadth of vocabulary knowledgeof Iranian English Foreign Language learners in their writing performance. Learners in intermediatelevel of language proficiency were cases of the study. To achieve this end, by administering OxfordQuick Placement Test to different groups of students studying English Translation and EnglishLiterature in Birjand University, 40 students were selected as the participants of the study; 20 of themwere grouped in lower-intermediate and 20 ones in upper-intermediate sublevel. Then to determinethe participants’ depth and breadth of vocabulary knowledge, Word Association Test (Read, 1993)and Vocabulary Level Test (Nation, 1990) were administered respectively. After two weeks, the testswere administered to them again following test-retest method to check the reliability of the tests.Then, two descriptive writing tests were administered and the papers were assessed base onComposition Profile of Jacob et al. (1981). Finally, Statistical Package for Social Sciences (SPSSsoftware) was used in order to analyze the data. The results of the correlation coefficients andregression analyses of the data indicated that there was a significant correlation between depth andbreadth of vocabulary knowledge and writing performance of upper-intermediate EFL learners,however, this was not so about lower-intermediate EFL learners; furthermore, there was a significantcorrelation between depth and breadth of vocabulary knowledge of both lower and upperintermediateEFL learners.