应用语言学研究的路径分析方法原理与应用评介

An Evaluation of the LISREL Program and Related EFL Studies in China

本文探讨LISREL计算机程序的统计学原理、操作系统和路径分析模型,指出线性结构方程模型是一种从变量间或变量群间的协方差结构出发,研究和确认因果关系的分析方法,共包括测量建模和结构建模二个模型。文章评述了我国应用语言学研究者运用该方法开展了英语写作和英语学习动机等方面的实证研究,指出LISREL方法是应用语言学与外语教学研究方法的有效方法之一。

This paper introduces the statistic principles,theoretical models and operations of the LISREL program.The method estimates the unknown coefficients of the set of linear structural equations.It is particularly designed to accommodate models that include latent variables,measurement errors in both dependent and independent variables,reciprocal causation,simultaneity,and interdependence.The LISREL model,in its most general form,consists of a set of linear structural equations.Vari - ables in the equation system may be either directly observed variables or unmeasured latent(theo - retical)variables that are not observed but relate to observed variables.It is assumed in the model that there is a causal structure among a set of latent variables,and that the observed variables are in - dicators of the latent variables.The model consists of two parts,the measurement model and the structural equation model.The measurement model specifies how latent variables or hypothetical constructs depend upon or are indicated by the observed variables.The structural equation model specifies the causal relationships among the latent variables,describes the causal effects,and assigns the explained and unexplained variance.The results of the LISREL analysis are interpreted by the overall goodness of fit of a model to the data.Five criteria are involved in the evaluation of the output:1)the value of X 2 relative to the degree of freedom;2)the probability that the true X 2 value is larger than the obtained value;3)the goodness of fit index(GFI);4)the root mean square residu - al(RMR);5)modification index(MI).If the model meets all the required values of the above crite - ria,then it can be said that the data fits the model well.Based on the path analysis approach,two LISREL - driven studies on Chinese EFL learners in recent literature are evaluated.The first investi - gates the effects of the English proficiency variables on the English writing of the Chinese EFL writers and describes the direct and indirect paths among the variables in question.The second study focuses on the internal motivational structure of the Chinese EFL learners by examining the motiva - tional variables affecting English learning.It constructs the path model of motivational factors af - fecting English outcome for the Chinese EFL learners.