Effects of Individual Optimization in Setting the Boundaries of Dichotomous Items on Accuracy of Estimation

Abstract

Applying the normal ogive model of latent trait theory, two sets of data, simulated and empirical, were analyzed. The objective was to determine how much accuracy of estimation of the subjects' latent ability can be maintained by tailoring for each testee the order of presentation of the items and the border of dichotomization for each item. This was compared to the information provided by the ori ginal graded test items. Results indicated that tailored testing is promising especially when the number of items is not too small, and that a graded item can effectively be used as the initial item in tailored testing because of its branching effect.