词汇特征量对CET作文得分的影响

The Relationship between Four Vocabulary Measures and CET-4/6 Essay Scores

本文旨在研究四种典型的词汇特征量，即标准类符形符比率、平均词长、低频词对高频词比率、实词密度，对CET作文得分的预测性。鉴于二语作文的特殊性，本研究还进一步探讨了错误和作文内容质量的协同性对这种预测性的干扰。结果表明，四种词汇特征量对CET作文得分并无较强的预测能力。CET作文中的错误影响到词汇特征量的测量信度，作文内容质量与词汇特征量之间的非协同发展并不是干扰词汇特征量对CET作文得分预测的主要因素。

This paper reports an effort to explore the score predictability of the four popular vocabulary measureslexical diversity, average word length, uncommon-common word ratio, and lexical density for CET-4/6 essays. In light of the difference between L1 and L2 essays, this study also delves into two distorting factors-the error and non- concurrence between different writing quality aspects. Findings of the study indicate that the four vocabulary measures do not possess strong power in predicating CET-4/6 essay scores. However, the error percentage bears significant correlation with essay scores and it is significant enough to distort the reliability of lexical feature measurements. Besides, the quality of content does not tend to covariate with vocabulary measures in CET-4/6 essays, whereas it is highly correlated with essay scores. Therefore, CET-4/6 test takers＇ poor use of language is probably the true ringleader that makes four vocabulary measures fail to predict CET-4/6 essay scores.