3参数等级反应模型及其参数估计

Three-Parameter Graded Response Model and Its Parameter Estimation

基于Samejima等级反应模型,将项目猜测度融合到3参数等级反应模型中,且开发了相应的项目参数估计程序,使用模拟数据和实测数据对程序进行了检验;并且证明了如果忽略项目的猜测度,会使能力估计的精度虚假地升高.

Replacing 2-parameter Logistic model in Samejima＇s Graded Response Model with 3-parameter Logistic model,the 3PL-GRM is proposed and the program of estimation of unknown parameters in the new model was developed.To verify the available utility of the program,some Monte Carlo simulations and empirical study were made.It was proved that the Fisher information of 3PL-GRM is smaller than that of GRM.It means that the item information decreases along with guessing parameter increasing,so the estimation of ability parameter is not accurate with ignoring guessing.