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 - TY - JOUR T1 - Evaluating the usefulness of computerized adaptive testing for medical in-course assessment JF - Academic Medicine Y1 - 1999 A1 - Kreiter, C. D. A1 - Ferguson, K. A1 - Gruppen, L. D. KW - *Automation KW - *Education, Medical, Undergraduate KW - Educational Measurement/*methods KW - Humans KW - Internal Medicine/*education KW - Likelihood Functions KW - Psychometrics/*methods KW - Reproducibility of Results AB - PURPOSE: This study investigated the feasibility of converting an existing computer-administered, in-course internal medicine test to an adaptive format. METHOD: A 200-item internal medicine extended matching test was used for this research. Parameters were estimated with commercially available software with responses from 621 examinees. A specially developed simulation program was used to retrospectively estimate the efficiency of the computer-adaptive exam format. RESULTS: It was found that the average test length could be shortened by almost half with measurement precision approximately equal to that of the full 200-item paper-and-pencil test. However, computer-adaptive testing with this item bank provided little advantage for examinees at the upper end of the ability continuum. An examination of classical item statistics and IRT item statistics suggested that adding more difficult items might extend the advantage to this group of examinees. CONCLUSIONS: Medical item banks presently used for incourse assessment might be advantageously employed in adaptive testing. However, it is important to evaluate the match between the items and the measurement objective of the test before implementing this format. VL - 74 SN - 1040-2446 (Print) N1 - Kreiter, C DFerguson, KGruppen, L DUnited statesAcademic medicine : journal of the Association of American Medical CollegesAcad Med. 1999 Oct;74(10):1125-8. JO - Acad Med ER -