Abstract

It is true that lexical complexity is an important predictor of students’ language proficiency. A great number of studies have been carried out to investigate the lexical complexity in written and oral productions of second language learners. However, few studies have focused on whether different task types will affect lexical complexity or not.
This study explore the lexical complexity in English majors’ writings across two task types, namely, summary and comment. The participants of the current study are 55 second year English majors in university who have learned English for 9-12 years. When they graduated from senior high school, they all did very well in the English test in the University Entrance Examination. In this study, the measures of lexical complexity include lexical variation, lexical density and lexical sophistication. With the help of the computer program including RANGE 32 and SPSS, the researcher successfully collected the data in lexical variation, lexical density, and lexical sophistication between two different task types (summary and comment).
The results reveal that different task types can affect the lexical complexity. In this study, the statistics reveal that summary tends to have a relatively higher ratio of lexical complexity in all of the three measurements: lexical variation, lexical density, and lexical sophistication. The results implicate that teacher can use summary as the way of enhancing students’ lexical proficiency.

Key words: task types; lexical complexity; lexical variation; lexical density; lexical sophistication; English writing

摘 要

词汇复杂度是衡量学生语言水平高低的一个重要因素。学者们对二语学习者的书面和口语产出中的词汇复杂度进行了大量的调查研究。然而，却极少有研究关注不同的任务类型对词汇复杂度的影响。
本文探讨了英语专业学生的两种不同写作类型——摘要写作和评论写作对词汇复杂度是否有影响。本研究以大学英语系大二的55名学生为研究对象，他们平均学习英语的年数为9-12年，他们参加高考时在英语考试中均取得了优异的成绩。本研究所涉及的测量词汇复杂度的指标共有三个，即词汇多样性，词汇密度和词汇难度。在电脑软件RANGE 32 and SPSS的帮助下，本研究成功地收集了两个任务类型（摘要写作和评论写作）在词汇多样性，词汇密度和词汇复杂度的不同数据。
研究结果表明，不同的写作任务类型会影响词汇复杂度。在本研究中，数据显示摘要写作在词汇多样性，词汇密度以及词汇难度均相对高于评论写作。因此摘要写作的词汇复杂度要高于评论写作。此结果表明，教师可以将摘要写作作为提高学生词汇能力一种手段。

关键词：任务类型；词汇复杂度；词汇多样性；词汇密度；词汇难度；英语写作