基于GPCM的计算机自适应测验选题策略比较  

Item Selection Strategies for Computerized Adaptive Testing with the Generalized Partial Credit Model

作　　者：刘珍[1] 丁树良[1] 林海菁[1] 

机构地区：[1]江西师范大学信息工程学院

出　　处：《心理学报》2008年第5期618-625,共8页Acta Psychologica Sinica

基　　金：国家自然科学基金(60263005);江西省科技厅攻关项目;江西省教育厅科技项目;卫生部课题(JM20060070,KY200704);高等学校博士学科点专项科研基金(8020070414001)资助

摘　　要：选题策略是计算机自适应测验(Computerized Adaptive Testing,CAT)研究的一项重要内容,它的好坏直接关系到考试的信度、效度及考试的安全性。CAT的许多研究与应用,都建立在0-1二级评分模型基础上,对多级评分CAT的选题策略的研究很少报导。目前国内虽已开展了基于GRM的CAT研究,但基于GPCM的CAT的研究尚未见有关报道。本文通过计算机模拟程序,对基于拓广分部评分模型(Generalized Partial Credit Model,GPCM)下的CAT的四种选题策略在多种情况下进行了比较研究。研究结果表明:被试能力呈正态分布时,选题策略的使用效果与项目步骤参数分布有很大的关系。(1)项目步骤参数均服从正态分布时,采用能力与项目步骤参数匹配选题策略效果最佳;(2)项目步骤参数均服从均匀分布时,能力与项目步骤参数平均数匹配选题策略效果最佳。The objective of computerized adaptive testing （CAT） is to construct an optimal test for each examinee. Item Selection Strategy （ISS） is an important part of CAT research, whose quality is directly related to the reliability, efficiency, and security of the test. Many researches and applications of CAT are based on a dichotomously scored model. It is highly evident that more information can be obtained from examinees using a polytomously scored model rather than a dichotomous model. Moreover, it is necessary for us to further explore CAT research based on a polytomously scored model. Both the Generalized of a polytomously scored Partial Credit Modal （GPCM） and the Graded Response Model （GRM） are within the range model. However, they differ from each other. In the GRM, the item grade difficulties ascend monotonously as the grades increase; while the GPCM shows the performing process of the item, which is separated into some line-steps to put forwards. In the GPCM, each item contains several step parameters, and there are no specific rules governing them. The posterior step cannot advance when the earlier step has not been completed, and the posterior＇s step parameter may be lower than that of the previous one. Considerable research is already being conducted on CAT using the GRM; however, in our country, there are few reports pertaining to research on CAT using the GPCM. This study investigated the four types of ISS in comparison with CAT in various circumstances, using the GPCM through computer simulated programs. They are implemented in four item pools, and each item pool has a capacity of 1000 items. Each item has five step parameters; further, the discrimination parameter and step parameters are distributed as follows： b - N （0,1）, lna - N （0,1）, b - N （0,1）, a - U （0.2,2.5）, b - U （-3,3）, lna - N （0,1）, b - U （-3,3）, and a - U （0.2,2.5）. Item parameters are generated based on the Monte Carlo simulation method. Responses to the items are generated acco

关 键 词：IRT 多级评分模型 GPCM a-分层 选题策略 

分 类 号：B841[哲学宗教—基础心理学]