Lexical Demands and Features of English Textbooks for Vietnamese 10th Graders: An In-depth Comparison of Listening Sections

Abstract

English textbooks are the most pivotal learning materials in the EFL context. However, in Vietnam, English textbooks for general education are randomised by schools, which arouses a problem of whether these textbooks are equivalent for students to gain the same proficiency. By analysing the corpus of 54,566 tokens extracted from the listening transcripts of the grade-10 English textbook series, the study reported two studies on lexical demands and lexical richness. The first study profiled the corpus by AntwordProfiler using BNC/COCA wordlists with 4 supplementary lists to measure and compare the lexical demands of these textbooks. The results showed that these textbooks were quite equivalent in terms of lexical demands. In specific, students had to master around 1,000 word families to understand 85% of listening texts in all of these textbooks. In order to achieve 95% coverage, students needed about 2,000 to 3,000 word families. At the threshold of 98%, 3,000 to 4,000 word families were necessary to gain this coverage. Compared to the previous textbook, these new series were better for students’ comprehension. However, it still constraints students’ self-study. The second study focused deeply on lexical richness including lexical sophistication and lexical diversity to measure the difficulty of these textbooks. TAALED was run to calculate these features and compared them by the Jamovi program. The findings indicated that although these textbooks were insignificantly varied in lexical sophistication, they had significant differences in lexical diversity. It means that these textbooks had an equivalent quantity of advanced words, nonetheless, the number of new types in these textbooks was extremely different. Taken as a whole, the present research clarifies the support of these grade-10 textbooks in learning English vocabulary, even so, the feasibility of them are quite equivocal due to the significant differences in lexical diversity. Hence, the research heightens the roles of teachers in teaching and suggests textbook writers to carefully consider the design of these textbooks. Besides, the findings and limitations of this research also pave the way for other researchers who are fond of vocabulary and English textbooks.