The Sympson and Hetter (SH) (1985) method is the accepted method of probabilistic item-exposure control in computerized adaptive testing. However, setting its control parameters to admissible values requires an iterative process of computer simulations that has been found to be time consuming, particularly if the parameters have to be set conditional on a realistic set of values for the examinees’ ability parameter. Several formal properties of the method are given that help us explain why this iterative process can be slow and does not guarantee admissibility. In addition, some alternatives to the SH method are introduced. The behavior of these alternatives was estimated for an adaptive test from an item pool from the Law School Admission Test (LSAT). One of the alternatives showed particularly attractive behavior and converged smoothly to admissibility for all items in a relatively small number of iteration steps.
|Name||LSAC research report series - Computerized testing report|
|Publisher||Law School Admission Council|