混合题型的IRT等值问题研究

Research on IRT Equating for Multiple Item Types

我们称既有0-1评分题,又有多级评分题的试卷为混合题型试卷,简称为混合题型.以往国内对混合题型的测验等值采用的方法是将Logistic模型看成是等级反应模型或拓广的分部评分模型的特例,这种处理方式就可能忽略了项目的猜测因素.为了解决这一问题,本文将三参数的Logistic模型和GRM进行扩展得到混合模型,并针对此模型开发了相应的等值程序.另外,为了检验某次测验0-1评分项目存在猜测,而人为将其忽略所带来的误差大小,本文进行了大量的Monte Carlo模拟实验.实验结果表明,若某测验中0-1评分项目存在猜测而等值时忽略这一事实误用GRM,在绝大部分情况下都比用混合模型等值的误差大而且有显著性差异,并且等值的误差会随着猜测度的的增大而增大.

More test papers have adopted dichotomous scoring items and polytomous scoring items. This kind of paper was called Multiple Items Paper, for short, Multiple Items Type. In the past, the domestic test equating of multiple items type treated Logistic Model as the particular of GRM or GPCM, this approach may ignore the element of guessing. To solve this problem, this paper put forward a Mixed Model extended from 3PLM and GRM, which has solved the ignorance of guessing. Moreover, a relevant equating program has also been developed for the Mixed Model. In addition, in order to measure the error by the ignorance of guessing in a test, this paper has carried a lot of experiments of Monte Carlo Simulation. The finding shows, if GRM is used by the ignorance of the guessing in a test, there will be great divergence in equating and obvious difference compared to the Mixed Model mostly. Moreover, the divergence in equating will increase with the guessing increasing.