TY - JOUR T1 - Rotating item banks versus restriction of maximum exposure rates in computerized adaptive testing JF - Spanish Journal of Psychology Y1 - 2008 A1 - Barrada, J A1 - Olea, J. A1 - Abad, F. J. KW - *Character KW - *Databases KW - *Software Design KW - Aptitude Tests/*statistics & numerical data KW - Bias (Epidemiology) KW - Computing Methodologies KW - Diagnosis, Computer-Assisted/*statistics & numerical data KW - Educational Measurement/*statistics & numerical data KW - Humans KW - Mathematical Computing KW - Psychometrics/statistics & numerical data AB -

If examinees were to know, beforehand, part of the content of a computerized adaptive test, their estimated trait levels would then have a marked positive bias. One of the strategies to avoid this consists of dividing a large item bank into several sub-banks and rotating the sub-bank employed (Ariel, Veldkamp & van der Linden, 2004). This strategy permits substantial improvements in exposure control at little cost to measurement accuracy, However, we do not know whether this option provides better results than using the master bank with greater restriction in the maximum exposure rates (Sympson & Hetter, 1985). In order to investigate this issue, we worked with several simulated banks of 2100 items, comparing them, for RMSE and overlap rate, with the same banks divided in two, three... up to seven sub-banks. By means of extensive manipulation of the maximum exposure rate in each bank, we found that the option of rotating banks slightly outperformed the option of restricting maximum exposure rate of the master bank by means of the Sympson-Hetter method.

VL - 11 SN - 1138-7416 N1 - Barrada, Juan RamonOlea, JulioAbad, Francisco JoseResearch Support, Non-U.S. Gov'tSpainThe Spanish journal of psychologySpan J Psychol. 2008 Nov;11(2):618-25. ER - TY - JOUR T1 - Maximum information stratification method for controlling item exposure in computerized adaptive testing JF - Psicothema Y1 - 2006 A1 - Barrada, J A1 - Mazuela, P. A1 - Olea, J. KW - *Artificial Intelligence KW - *Microcomputers KW - *Psychological Tests KW - *Software Design KW - Algorithms KW - Chi-Square Distribution KW - Humans KW - Likelihood Functions AB - The proposal for increasing the security in Computerized Adaptive Tests that has received most attention in recent years is the a-stratified method (AS - Chang and Ying, 1999): at the beginning of the test only items with low discrimination parameters (a) can be administered, with the values of the a parameters increasing as the test goes on. With this method, distribution of the exposure rates of the items is less skewed, while efficiency is maintained in trait-level estimation. The pseudo-guessing parameter (c), present in the three-parameter logistic model, is considered irrelevant, and is not used in the AS method. The Maximum Information Stratified (MIS) model incorporates the c parameter in the stratification of the bank and in the item-selection rule, improving accuracy by comparison with the AS, for item banks with a and b parameters correlated and uncorrelated. For both kinds of banks, the blocking b methods (Chang, Qian and Ying, 2001) improve the security of the item bank.Método de estratificación por máxima información para el control de la exposición en tests adaptativos informatizados. La propuesta para aumentar la seguridad en los tests adaptativos informatizados que ha recibido más atención en los últimos años ha sido el método a-estratificado (AE - Chang y Ying, 1999): en los momentos iniciales del test sólo pueden administrarse ítems con bajos parámetros de discriminación (a), incrementándose los valores del parámetro a admisibles según avanza el test. Con este método la distribución de las tasas de exposición de los ítems es más equilibrada, manteniendo una adecuada precisión en la medida. El parámetro de pseudoadivinación (c), presente en el modelo logístico de tres parámetros, se supone irrelevante y no se incorpora en el AE. El método de Estratificación por Máxima Información (EMI) incorpora el parámetro c a la estratificación del banco y a la regla de selección de ítems, mejorando la precisión en comparación con AE, tanto para bancos donde los parámetros a y b correlacionan como para bancos donde no. Para ambos tipos de bancos, los métodos de bloqueo de b (Chang, Qian y Ying, 2001) mejoran la seguridad del banco. VL - 18 SN - 0214-9915 (Print) N1 - Barrada, Juan RamonMazuela, PalomaOlea, JulioResearch Support, Non-U.S. Gov'tSpainPsicothemaPsicothema. 2006 Feb;18(1):156-9. ER -