Vocabulary in Japanese EFL Textbooks: A Bidirectional Coverage Analysis

Textbooks developed based on the new Course of Study Guidelines have been in use since April 2021. One notable change can be seen in the increase of the variety of vocabulary words, from 1,200 words to between 1,600–1,800 words, that learners need to be familiar with before they graduate junior high school. In this study, vocabulary taught in these newly published textbooks designed for junior high school students in Japan will be assessed. For this purpose, a corpus of junior high school textbooks, which is sourced from one series of government-approved junior high school textbooks, is compared with the New General Service List (NGSL) that consists of 2,801 high-frequency words in general English. Results show that the textbook series is largely composed of vocabulary words contained in the NGSL with a greater than 95% coverage; however, it represents only a small part of the list with a smaller than 37% coverage. Additionally, breaking the NGSL down into 560-word frequency bands, the study investigates in which bands the textbook series focus and in which bands there is a deficiency. This distribution analysis indicates that words at higher frequency bands occur more frequently. The textbook series covers the first 560-word frequency band with a greater than 80% coverage, but the coverage levels sharply decrease after this band. Finally, pedagogical implications are suggested for textbook designers as well as for language learners.