deviation model meaning in English

偏差模型

First this paper analyses weighted deviation model ( wdm ) put forward by len swanson & martha l . stocking . it is found that when the constraints are made up of question numbers , question grades and other information with different dimensions , the calculated values of dl , du cannot be compared . then the wdm model is further improved and the constraints of the model are simplified in the way that only the question grades are strictly constrained while other constraints are reflected by the distribution of grades
首先，本文对lenswanson & marthal . stocking提出的离差加权模型( weighteddeviationsmodel ，简称wdm模型)进行分析，发现当约束条件既有题数，又有题分和信息量时，由于各约束条件的单位(量纲)不同，根据约束条件计算出的d _ l _ j ， d _ u _ j的值不可比。