TY - JOUR T1 - Controlling item exposure and test overlap on the fly in computerized adaptive testing JF - British Journal of Mathematical and Statistical Psychology Y1 - 2008 A1 - Chen, S-Y. A1 - Lei, P. W. A1 - Liao, W. H. KW - *Decision Making, Computer-Assisted KW - *Models, Psychological KW - Humans AB - 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. VL - 61 SN - 0007-1102 (Print)0007-1102 (Linking) N1 - Chen, Shu-YingLei, Pui-WaLiao, Wen-HanResearch Support, Non-U.S. Gov'tEnglandThe British journal of mathematical and statistical psychologyBr J Math Stat Psychol. 2008 Nov;61(Pt 2):471-92. Epub 2007 Jul 23. ER - TY - JOUR T1 - The effect of item pool restriction on the precision of ability measurement for a Rasch-based CAT: comparisons to traditional fixed length examinations JF - J Outcome Meas Y1 - 1998 A1 - Halkitis, P. N. KW - *Decision Making, Computer-Assisted KW - Comparative Study KW - Computer Simulation KW - Education, Nursing KW - Educational Measurement/*methods KW - Human KW - Models, Statistical KW - Psychometrics/*methods AB - This paper describes a method for examining the precision of a computerized adaptive test with a limited item pool. Standard errors of measurement ascertained in the testing of simulees with a CAT using a restricted pool were compared to the results obtained in a live paper-and-pencil achievement testing of 4494 nursing students on four versions of an examination of calculations of drug administration. CAT measures of precision were considered when the simulated examine pools were uniform and normal. Precision indices were also considered in terms of the number of CAT items required to reach the precision of the traditional tests. Results suggest that regardless of the size of the item pool, CAT provides greater precision in measurement with a smaller number of items administered even when the choice of items is limited but fails to achieve equiprecision along the entire ability continuum. VL - 2 N1 - 983263801090-655xJournal Article ER -