自动评分系统在二语写作教学中的反馈效果实证研究

An Empirical Study on the Effectiveness ofAutomated Essay Scoring in EFL Writing

教学实践和研究实验发现作文自动评分系统(AES)对于提高学生的二语写作能力发挥着比较积极的作用。本文以句酷批改网为例,探究学生利用自动评分系统多次修改后所提交作文,在词汇、句法、结构、规范四大维度上的变化,研究发现AES对于学生英语写作词汇、写作规范的影响较大,这其中又以学术词汇密度、高频词汇密度、类符形符比以及拼写正确率和病句数的变化最为明显。因此,作文自动评分系统对于学生二语写作的反馈是及时且有效的。研究最后针对现有的AES不足之处提出了几点建议。

Many teaching practices and experimental studies show that AES(Automated Essay Scoring)has been playing an active role in improving EFL learners’writing.Taking an example of Pigai,one popular domestic AES,the research focuses on the changes in students’EFL writing concerning such dimensions as vocabulary,syntax,structure and conventions by comparing the first draft and last draft that students submitted after they have revised their essays for several times ranging from 5 to 36,which have been long used as the main criterions to evaluate EFL writing.With statistic analysis,it is found that Pigai has exerted a more positive influence on vocabulary and conventions with statistically significant differences in academic vocabulary ratio,high-frequency vocabulary ratio,and Type/Token Ratio(a ratio to indicate the richness of vocabulary)as well as number of grammatically wrong sentence and spelling.Taking use of the feedback of Pigai,students have learned to use more academic words,have a better command of high-frequency vocabulary,and have developed the richness of their vocabulary in their EFL writing.Meanwhile,their spelling mistakes and grammatically wrong sentences have sharply decreased.It is safe to draw a conclusion that the feedback of AES is timely and effective,especially in the perspectives of vocabulary and writing conventions.Besides,it is also proved that students have made some improvement in other sub-dimensions concerning syntax and structure like clause type and the essay layout.Nevertheless,AES indeed has some drawbacks resulting from insufficiency of building corpus and developing natural language.Since it is less effective in evaluating the content and idea of an essay,a few suggestions have been also put forward including building a larger corpus and a more effective mode to evaluate EFL writings to ultimately improve the EFL teaching.