Vocabulary instruction: Textbook analysis of the Outcomes series

Abstract

Even though textbooks are central to language teaching, linguistic research on how well some commercial textbook series support vocabulary acquisition is not comprehensive. As a result, many instructors lack both practical tools and empirical support regarding the choice of materials appropriate for their students' goals. This study presents a corpus-based analysis of the vocabulary coverage in the Outcomes textbook series, Third Edition, published by National Geographic. Using two vocabulary profiler tools (Compleat Lexical Tutor by Cobb, 1998; AntWordProfiler by Anthony, 2024), in combination with a qualitative analysis of the textbooks, this paper examines lexical coverage, frequency distribution, opportunities for vocabulary recycling, and the inclusion of vocabulary learning strategies across six proficiency levels. The analysis shows that lower-level books include a larger percentage of high-frequency vocabulary. As students progress through the course, they are expected to encounter a higher number of mid-frequency and low-frequency vocabulary. However, opportunities for vocabulary recycling vary considerably across the textbooks and specific vocabulary items. Even though the book is recommended for IELTS preparation, the findings indicate limited academic vocabulary coverage. This suggests that the textbook series might be more suitable for general English classrooms than for academic or test-focused contexts. Lastly, the series lacks explicit guidance on vocabulary learning strategies, which may limit learners' ability to independently consolidate lexical knowledge. The study highlights the value of corpus-informed textbook evaluation and offers pedagogically relevant insights for teachers, material developers, and curriculum designers.