JALT2025 - Tokyo

Readability and Lexical Complexity in High School Textbooks

Oct 31, 2025, 3:25 PM

30m

National Olympics Memorial Youth Center / 国立オリンピック記念青少年総合センター

Research-oriented Presentation (30-minutes) Materials and Assessment Room 405

Speakers

Shunsuke Ito (Tokyo University of Pharmacy and Life Sciences) Tomomi Sasaki (Tokyo University of Pharmacy and Life Sciences)

Description

This study examines the readability progression of Japanese high school English textbooks over three years and its correlation with vocabulary complexity using the New JACET8000 wordlist. Analyzing 70 volumes from 24 textbook series, the study identifies four readability patterns and finds that 14 of 22 textbooks align with curricular expectations. Higher readability scores correspond to increased lexical complexity. These findings highlight the link between readability and vocabulary, offering insights for textbook development and curriculum design.

Summary

This study examines the readability progression of Japanese high school English textbooks over three years and its correlation with vocabulary complexity using the New JACET8000 wordlist. Analyzing 70 volumes from 24 textbook series, the study identifies four readability patterns and finds that 14 of 22 textbooks align with curricular expectations. Higher readability scores correspond to increased lexical complexity. These findings highlight the link between readability and vocabulary, offering insights for textbook development and curriculum design.