[Item selection rules in a Computerized Adaptive Test for the assessment of written English]

Item selection rules in a Computerized Adaptive Test for the assessment of written English. e-CAT is a Computerized Adaptive Test for the evaluation of written English knowledge, using the item selection rule most commonly employed: the maximum Fisher information criterion. Some of the problems of this criterion have a negative impact in the estimation accuracy and in the item bank security. In this study, the performance of this item selection rule is compared, by means of simulation, with two other rules: selecting the item with maximum Fisher information in an interval (Veerkamp y Berger, 1997) and a new criterion, called "maximum Fisher information in an interval with geometric mean". In general, this new rule shows smaller measurement error and smaller item overlap rates. It seems, thus, recommendable, as it allows the simultaneous improvement of estimation accuracy and the maintenance of the item bank security of e-CAT.