摘要：This quantitative study aimed at measuring L2 lexical richness of productive vocabulary in the written production of Iranian EFL university students. In fact, this work was conducted to find out how rich the productive vocabulary of Iranian EFL university students is. Productive vocabulary knowledge is to express meaning through speaking or writing, retrieve and produce the appropriate spoken or written word form (Nation, 2001). Considering the importance of size and level of this knowledge among language learners, 210 writing samples such as final examinations and homework assignments of EFL undergraduate students majoring translation at BA level in semesters 2, 4, 6, and 8 at Islamic Azad University, Khorasgan branch, were analyzed by LFP (a tool to measure lexical richness in written texts). The generated profiles matched with available vocabulary frequency lists. The results of this work indicated an increase in the students’ ability to use their lexical knowledge throughout years of study at university. However, this knowledge is under the suggested threshold proposed by recent studies. The findings of the research can shed light on the relationship between vocabulary growth and different input conditions. The results of this work can provide insights for language teachers and program planners in developing appropriate materials for enriching vocabulary among learners more effectively.
