Abstract
This study investigated the relationship between learners' vocabulary size and reading comprehension of academic texts. A reading comprehension test based on the TOEFL and an online receptive vocabulary size test were administered to 175 pre-intermediate Japanese EFL university students. The findings showed that (1) TOEFL texts could actually be considered academic, (2) 5000 to 5500 words of the JACET 8000 basic words covered 95% of the words used in the TOEFL reading section, (3) the estimated vocabulary size of 6500 is needed to score more than 60% on the reading comprehension section of the TOEFL, and (4) there were no strong relationships between vocabulary knowledge and reading sub-skills. This paper argues that the relationship between learners' vocabulary size and reading success is not so straightforward.
