2022 개정교육과정에 따른 고등학교 1학년 영어 교과서 읽기 자료의 난이도 분석 연구

Text difficulty in grade 10 English textbooks under Korea’s 2022 revised curriculum: A Coh-Metrix analysis of reading passages

This study evaluates whether Grade 10 Common English 1 and Common English 2 textbooks developed under Korea’s 2022 English curriculum embody hierarchical progression across publishers and lessons. We compiled a corpus of 80 core reading passages and analyzed 23 Coh-Metrix indices representing length, lexical maturity, syntactic complexity, cohesion, and readability. Given small per-group samples, we employed nonparametric tests. Results show limited publisher differences in Common English 1 (notably sentence length and left embeddedness) but broader, significant disparities in Common English 2 spanning word count, sentence length, lexical frequency/age of acquisition, cohesion, and FKGL. Common English 2 consistently exceeds Common English 1 in length, syntactic depth , lexical maturity, cohesion, and difficulty, evidencing curricular upward progression. Lesson-wise, Common English 2 exhibits systematic increases across key indices, whereas Common English 1 shows only a modest rise in sentence length. Findings support data-informed textbook development and review (e.g., target bands for core indices) and classroom scaffolding aligned to complexity. Limitations include small lesson-level samples and reliance on monotonic trend tests; future research should employ larger corpora and mixed-effects modeling.