Language Complexity of the Listening Scripts of the High School English Ⅰ and Ⅱ Textbooks Based on the 2015 Revised National Curriculum

This paper discusses the ideal characteristics of listening materials of English textbooks within the framework of the 2015 Revised National Curriculum of English, emphasizing two key principles: Tolerance (or Allowable Deviation) and Continuity. Tolerance refers to the need for textbooks to strike a balance in linguistic complexity. English textbooks should feature texts that are neither overly complex nor too simplistic, ensuring that they are appropriately challenging compared to other textbooks covering the same subject. This balance helps to maintain a consistent level of difficulty across materials, catering to diverse student capabilities without overwhelming or under-stimulating learners. Continuity suggests that English textbooks should be more linguistically complex and longer in length than those intended for lower-ranking subjects in the curriculum. This progression supports students’ development, preparing them for increasingly sophisticated language use as they advance through their education. The study evaluated nine sets of the listening scripts of high school English I and II textbooks, employing two-way (M)ANOVAs to analyze the effects of the subject and the publisher on six linguistic complexity indices: AG, TTR, MCI, MLC, DP/C, and CP/C. The findings revealed that a considerable number of the nine textbooks failed to meet the established Tolerance and Continuity standards on multiple occasions. This calls for a reevaluation of how English textbooks are chosen and assessed to ensure that they effectively support student learning in line with curriculum expectations. Enhancing the criteria for textbook selection could lead to more effective teaching materials that better serve the diverse needs of students.