被试作答的偶然性对IRT能力估计的影响研究

被试能力参数估计是项目反应理论应用研究最重要的技术之一。本文在理想的测验情境下，研究被试作答的偶然性对被试能力值估计的影响。研究设计了被试作答的两种偶然性情况：一是偶然做对了一道项目难度高于其能力值的试题，二是偶然做错了一道或几道项目难度低于其能力值的试题．然后分别探讨了这两种情况下对被试的能力估计所带来的影响，并且就如何消除这些偶然性所带来的影响提出了相应的方法。

The Influence of Haphazard Response on the Ability Estimation within the Item Response Theory

Ability parameter estimation is one of the important techniques in the Item Response Theory.In the idealized test,the authors studied how much the haphazard of examinees' response affected the estimation of their ability.Two haphazard situations were designed: one in which the examinee made a correct response to an item which normally was beyond their ability;the other in which the examinee made a wrong response to an which normally was beyond their ability.The authors discussed the different influences on the ability estimation in these two situations,and came up with their solutions to the problems concerned.