There is a prevailing belief that second language (L2) textbooks should strive for authenticity, aiming to accurately and reliably represent natural language use. However, assessing the authenticity of language textbooks is not a straightforward task, as it requires both a comparison between instructional texts and real-world language use and a consideration of the comparison within the broader context of language development. This study employs a corpus-based approach to examine word use in 31 widely used commercial textbooks across different proficiency levels, which serve as the primary resource for teaching, learning, and assessment in Chinese language programs at US universities. Using hierarchical cluster analysis, Zipf’s law analysis, and descriptive statistics, we found supportive evidence for the authenticity of word use in Chinese textbooks from a developmental perspective. Specifically, our findings reveal a nuanced gradation in the distribution of words across proficiency levels within these Chinese textbooks. Moreover, as proficiency levels increase, there is a discernible register shift in word use from spoken to written discourse. These observations carry significant implications for the utility of textbooks in Chinese language programs, particularly in the realms of instruction and assessment.

中文翻译：

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从发展的角度来看，教科书是真实的吗？美国大学中文教材词汇使用语料库分析

人们普遍认为第二语言（L2）教科书应力求真实性，旨在准确可靠地表现自然语言的使用。然而，评估语言教科书的真实性并不是一项简单的任务，因为它既需要对教学文本与现实世界的语言使用进行比较，又需要在更广泛的语言发展背景下考虑比较。本研究采用基于语料库的方法来检查 31 种不同熟练程度的广泛使用的商业教科书中的单词使用情况，这些教科书是美国大学汉语课程教学、学习和评估的主要资源。利用层次聚类分析、齐普夫定律分析和描述性统计，我们从发展的角度找到了支持汉语教科书词汇使用真实性的证据。具体来说，我们的研究结果揭示了这些中文教科书中不同熟练程度的单词分布存在细微差别。此外，随着熟练程度的提高，词语使用从口语到书面语的语域出现了明显的转变。这些观察结果对于汉语课程中教科书的实用性具有重要意义，特别是在教学和评估领域。