Rasch模型在CET考试分数等值中的应用  

Rasch Model Applied to Score Equating in the College English Test

作　　者：朱正才[1] 杨惠中[1] 杨浩然[1] 

机构地区：[1]上海交通大学外国语学院,上海200030

出　　处：《现代外语》2003年第1期69-75,共7页Modern Foreign Languages

摘　　要：本文详细描述了Rasch模型在中国大学英语四、六级考试的分数等值系统中的应用情况,并使用真实考试数据进行了Rasch模型背景下的分数等值实验,对分数等值过程中的诸多问题进行详尽的分析和探讨。Of all the facets of Item Response Theory, the Rasch model for dichotomously scored items is probably the most widely recognized by practitioners. In College English Test (CET) of China, this model has been used for 15 years and a lot of data yielded about score equating. This paper presents a description in detail of CET score equating process based on Rasch model and a pilot study with the CET test data. For equating purposes, a comparative test is given to a randomly sampled group of candidates at selected observation universities one week before each of the live CET test. The trial test paper is the one used on the norm group (e.g., the 1987 paper). Insignificant variance between the performances of candidates on the comparative test and performances of the norm group would indicate little change in ability level; if, then, significant differences resulted from the live CET test, it would mean a change in the difficulty level of the test. Since 1990, the Rasch model has been adopted to equate CET scores. As the comparative test paper and the present test paper are administered on the same group of candidates, items from both papers can be put on the same ability scale, making equating possible. In this process, an equating model is built on a random sample of candidature before it is applied to the whole test population. It is essential that the comparative test should be administered under quality control so that the data gathered are also reliable. As the comparative test and the live test are administered on the same group of candidates, with a time interval of only one week, time and proficiency level cannot be the main factors that affect the test results. Besides, since items used on the CET are designed by well-trained specialists under thorough quality control, and since they have been pre-tested and analyzed, with the overall difficulty level of the test rigorously controlled, no significant differences should exist between the results of these two tests. The above factors excluded, only two reasons

关 键 词：题目反应理论 分数等值 RASCH模型 

分 类 号：H030[语言文字—语言学]