外语课堂师生话语的促学特征研究——来自师生话语关联度的证据

The Learning-Promotion Features in Foreign Language Classrooms:Evidence from the Correlates between Teacher and Student Talk

本研究使用基于R的文本挖掘技术手段,研究两个平行班级的完整课堂话语,以项频率(tf)以及项频率-逆文档频率(tf-idf)值为技术指标,通过挖掘课堂话语中各角色话语的关联度,呈现不同外语课堂的语言对齐程度与师生互动的过程,从而探讨外语教师课堂话语的促学特征在内容与形式上的表现。研究发现,从项频率的总体指标看,两个平行班级的师生话语都与参照话语显著相关。但是,从课堂话语中各角色话语所用单词承载的信息权重看,两个平行班级的师生话语都“离题”了,都没有触及到所学课文中由最重要的词语所定义的核心内容,关联度很低。不过,两个平行班级的教师话语都表现出与学生积极互动并对学生积极进行反馈的促学特征。文本挖掘技术为动态发展的课堂话语的量化分析提供了新的路径。

This study uses text mining tools with R to investigate the correlates in English as a foreign language(EFL)student-teacher classroom talk with an attempt to address the learning-promotion features in foreign language classrooms.The teaching materials and the transcripts of two parallel classes are analyzed through term frequency(tf)and inverse document frequency(tf-idf)to demonstrate the degrees of linguistic alignment in different foreign language classes and how the learning-promoting mechanism works based on the contents and forms of classroom discourse.It is found that the discourse of both classes is significantly correlated with the baseline discourse(i.e.,the teaching materials)at the level of word frequency.However,zooming in on the term weight of the discourse using tf-idf,the teacher and student talk of both classes show a low degree of relevance to the teaching materials.It should nevertheless be noted that the teacher talk in both classes demonstrates some learning-promoting features such as vigorous student-teacher interaction and instant feedback conveyed by various response tokens in the teacher talk.This study shows that text mining tools can provide new ways of quantifying the dynamics of classroom discourse.