Chen Shu-Ying, Lei Pui-Wa, Liao Wen-Han
Department of Psychology, National Chung-Cheng University, Taiwan, ROC.
Br J Math Stat Psychol. 2008 Nov;61(Pt 2):471-92. doi: 10.1348/000711007X227067. Epub 2007 Jul 23.
This paper proposes an on-line version of the Sympson and Hetter procedure with test overlap control (SHT) that can provide item exposure control at both the item and test levels on the fly without iterative simulations. The on-line procedure is similar to the SHT procedure in that exposure parameters are used for simultaneous control of item exposure rates and test overlap rate. The exposure parameters for the on-line procedure, however, are updated sequentially on the fly, rather than through iterative simulations conducted prior to operational computerized adaptive tests (CATs). Unlike the SHT procedure, the on-line version can control item exposure rate and test overlap rate without time-consuming iterative simulations even when item pools or examinee populations have been changed. Moreover, the on-line procedure was found to perform better than the SHT procedure in controlling item exposure and test overlap for examinees who take tests earlier. Compared with two other on-line alternatives, this proposed on-line method provided the best all-around test security control. Thus, it would be an efficient procedure for controlling item exposure and test overlap in CATs.
本文提出了一种带有测试重叠控制的Sympson和Hetter程序（SHT）的在线版本，该版本可以即时在项目和测试层面提供项目曝光控制，而无需进行迭代模拟。该在线程序与SHT程序类似，即使用曝光参数同时控制项目曝光率和测试重叠率。然而，在线程序的曝光参数是即时顺序更新的，而不是通过在计算机化自适应测试（CAT）运行之前进行的迭代模拟来更新。与SHT程序不同，即使项目库或考生群体发生了变化，在线版本也可以在不进行耗时的迭代模拟的情况下控制项目曝光率和测试重叠率。此外，研究发现，对于较早参加测试的考生，在线程序在控制项目曝光和测试重叠方面比SHT程序表现更好。与其他两种在线方法相比，这种提出的在线方法提供了最佳的全方位测试安全控制。因此，它将是一种在CAT中控制项目曝光和测试重叠的有效程序。
