the role of collocation and vocabulary size in the writing performance of upper-intermediate students in iran

Vocabulary and collocation may contribute to effective communication. this study attempted to understand whether vocabulary size or collocation knowledge of upper-intermediate iranian efl learners better predicts their writing performance. for this purpose, three different tests including vocabulary size test (nation and beglar, 2007) collocation knowledge test (nizonkiza, 2012), and a writing performance task were administered to sixty students. the results, analyzed through linear regression, showed that while both vocabulary size (β = .521, p= .00) and collocation knowledge (β = .268, p= .03) were important factors in efl learners' writing performance, vocabulary size was a better predictor of the students’ writing performance.