@article {16,
	title = {Maximum information stratification method for controlling item exposure in computerized adaptive testing},
	journal = {Psicothema},
	volume = {18},
	number = {1},
	year = {2006},
	note = {Barrada, Juan RamonMazuela, PalomaOlea, JulioResearch Support, Non-U.S. Gov{\textquoteright}tSpainPsicothemaPsicothema. 2006 Feb;18(1):156-9.},
	month = {Feb},
	pages = {156-159},
	edition = {2007/02/14},
	abstract = {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.M{\'e}todo de estratificaci{\'o}n por m{\'a}xima informaci{\'o}n para el control de la exposici{\'o}n en tests adaptativos informatizados. La propuesta para aumentar la seguridad en los tests adaptativos informatizados que ha recibido m{\'a}s atenci{\'o}n en los {\'u}ltimos a{\~n}os ha sido el m{\'e}todo a-estratificado (AE - Chang y Ying, 1999): en los momentos iniciales del test s{\'o}lo pueden administrarse {\'\i}tems con bajos par{\'a}metros de discriminaci{\'o}n (a), increment{\'a}ndose los valores del par{\'a}metro a admisibles seg{\'u}n avanza el test. Con este m{\'e}todo la distribuci{\'o}n de las tasas de exposici{\'o}n de los {\'\i}tems es m{\'a}s equilibrada, manteniendo una adecuada precisi{\'o}n en la medida. El par{\'a}metro de pseudoadivinaci{\'o}n (c), presente en el modelo log{\'\i}stico de tres par{\'a}metros, se supone irrelevante y no se incorpora en el AE. El m{\'e}todo de Estratificaci{\'o}n por M{\'a}xima Informaci{\'o}n (EMI) incorpora el par{\'a}metro c a la estratificaci{\'o}n del banco y a la regla de selecci{\'o}n de {\'\i}tems, mejorando la precisi{\'o}n en comparaci{\'o}n con AE, tanto para bancos donde los par{\'a}metros a y b correlacionan como para bancos donde no. Para ambos tipos de bancos, los m{\'e}todos de bloqueo de b (Chang, Qian y Ying, 2001) mejoran la seguridad del banco.},
	keywords = {*Artificial Intelligence, *Microcomputers, *Psychological Tests, *Software Design, Algorithms, Chi-Square Distribution, Humans, Likelihood Functions},
	isbn = {0214-9915 (Print)},
	author = {Barrada, J and Mazuela, P. and Olea, J.}
}
@article {144,
	title = {A study of psychologically optimal level of item difficulty},
	journal = {Shinrigaku Kenkyu},
	volume = {65},
	number = {6},
	year = {1995},
	note = {Fujimori, SClinical TrialControlled Clinical TrialEnglish AbstractJapanShinrigaku kenkyu : The Japanese journal of psychologyShinrigaku Kenkyu. 1995 Feb;65(6):446-53.},
	month = {Feb},
	pages = {446-53},
	edition = {1995/02/01},
	abstract = {For the purpose of selecting items in a test, this study presented a viewpoint of psychologically optimal difficulty level, as well as measurement efficiency, of items. A paper-and-pencil test (P \& P) composed of hard, moderate and easy subtests was administered to 298 students at a university. A computerized adaptive test (CAT) was also administered to 79 students. The items of both tests were selected from Shiba{\textquoteright}s Word Meaning Comprehension Test, for which the estimates of parameters of two-parameter item response model were available. The results of P \& P research showed that the psychologically optimal success level would be such that the proportion of right answers is somewhere between .75 and .85. A similar result was obtained from CAT research, where the proportion of about .8 might be desirable. Traditionally a success rate of .5 has been recommended in adaptive testing. In this study, however, it was suggested that the items of such level would be too hard psychologically for many examinees.},
	keywords = {*Adaptation, Psychological, *Psychological Tests, Adult, Female, Humans, Male},
	isbn = {0021-5236 (Print)0021-5236 (Linking)},
	author = {Fujimori, S.}
}
