Abstract Second language writing research has often analyzed written discourse to provide evidence on learner language development; however, single word-based analyses have been found to be insufficient in capturing learner language development (Read & Nation, 2006). This study therefore utilized both single word-based and multi-word analyses. Specifically, it explored vocabulary distributions and lexical bundles to better understand the development of writing proficiency across three levels in an English Placement Test corpus (EPT) (N = 1388). Inference tests for multiple population proportions were conducted to compare statistical differences in the proportions of vocabulary and lexical bundle distributions across all group levels. The results suggested that higher proficiency learners used a higher number of types, tokens, and word families than lower proficiency learners. Regarding lexical bundles, noun phrase-based and verb phrase-based bundles with referential and stance functions were significantly found in lower-level responses. Preposition phrase-based bundles were significantly used in higher-level written discourse. This study suggests the importance of vocabulary and lexical bundles in academic writing, the necessity of including these features identified in this study in a second language writing curriculum, and the need to incorporate these features prevalent in a rating scale for assessments of academic writing.

中文翻译：

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非母语学术写作中词汇特征的使用

摘要 第二语言写作研究经常分析书面语篇，为学习者语言发展提供证据；然而，已发现基于单个单词的分析不足以捕捉学习者的语言发展（Read & Nation，2006 年）。因此，本研究同时使用了基于单字和多字的分析。具体来说，它探索了词汇分布和词汇包，以更好地了解英语分级测试语料库 (EPT) (N = 1388) 三个级别的写作能力发展。进行了多个人口比例的推理测试，以比较所有组级别的词汇和词汇束分布比例的统计差异。结果表明，熟练程度越高的学习者使用的类型、标记、和词族比低熟练度的学习者。关于词汇束，在较低级别的响应中显着发现了具有指称和立场功能的基于名词短语和基于动词短语的束。基于介词短语的包在更高级别的书面话语中得到了显着的使用。本研究表明词汇和词汇束在学术写作中的重要性，将本研究中确定的这些特征纳入第二语言写作课程的必要性，以及将这些普遍存在的特征纳入学术写作评估量表中的必要性。基于介词短语的包在更高级别的书面话语中得到了显着的使用。本研究表明词汇和词汇束在学术写作中的重要性，将本研究中确定的这些特征纳入第二语言写作课程的必要性，以及将这些普遍存在的特征纳入学术写作评估量表中的必要性。基于介词短语的包在更高级别的书面话语中得到了显着的使用。本研究表明词汇和词汇束在学术写作中的重要性，将本研究中确定的这些特征纳入第二语言写作课程的必要性，以及将这些普遍存在的特征纳入学术写作评估量表中的必要性。