摘要
本文首先用马尔科夫链蒙特卡洛(MCMC)算法和EM算法进行IRT模型参数估计模拟实验,并探讨了两种算法的参数估计精度,然后在分析三参数Logistic(3PL)模型参数估计精度的基础上改进模型并对其进行参数估计。结果表明,MCMC算法估计IRT模型的参数精度均优于EM算法,并且MCMC算法在估计3PL模型参数方面具有更明显的优势;在样本量较小的情况下,MCMC算法能较好地估计3PL模型参数,估计精度略低于2PL模型;3PL模型的项目参数确定性低是参数估计精度略低于2PL模型的主要原因;采用改进模型可以提高项目参数的确定性,进而得到更优的参数估计精度。
Simulation experiments on the parameter estimation of the item response theory(IRT) model were carried out with markov chain monte Carlo(MCMC) algorithm.Then the veracity of the parameter estimation with MCMC algorithm was compared with EM algorithm,the reason why the veracity of the parameter estimation of the 3PL model was worse was investigated,and the improvement of the 3PL model was tried out.The veracity of parameter estimation with MCMC algorithm was found to be better than that with EM algorithm.The MCMC algorithm was also effective in estimating the parameters of the 3PL model,even if the veracity of the parameter estimation of the 3PL model was not as high as that of the 2PL model.The key reason for the worse veracity of the parameter estimation of the 3PL model was the poor identifiability of its item parameters.The Improved - 3PL model could increase the distinguishability of item parameters,and then the veracity of its item parameters estimation was ter than standard 3PL model.
出处
《心理科学》
CSSCI
CSCD
北大核心
2010年第5期1212-1215,共4页
Journal of Psychological Science
基金
国家社科基金"十一五"规划课题(BBA080050)
江苏省教育科学"十一五"规划课题(D/2008/01/105)项目资助