Measuring Vocabulary Levels of English Textbooks and Tests Using a BNC Lemmatised High Frequency Word List

The purpose of this study was to create a means for comparing the vocabulary levels of Japanese junior and senior high school (JSH) texts, Japanese college qualification tests, English proficiency tests, and EGP, ESP and semi-ESP college textbooks in order to determine what the vocabulary levels are, and what additional vocabulary is required for students to understand 95% of these materials. This was done by creating a lemmatised and ranked high frequency word list (BNC HFWL) from the British National Corpus. This study found that although most college students should be prepared to take the TOEIC, and high school students should be able to pass both the Daigaku Center Nyushi and Eiken 2 grade tests, most college entrance exams contain vocabulary that is significantly above the level of high school graduates. Specialized vocabulary lists can be helpful in bridging vocabulary gaps between JSH and ESP, and between JSH and the TOEFL.