Abstract
A simulation study of a sequential computerized mastery test is carried out with items modeled with the 3 parameter logistic item response theory model. The examinees' responses are either identically distributed, not identically distributed, or not identically distributed together with estimation errors in the item characteristics. The simulations indicated that the observed results from the operating characteristic function differ significantly from the theoretical results, which is probably due to the use of an approximation formula. The mean number of items in a test, the distribution of test length, and the variance depend highly on how well we know the true values of the item characteristics and whether they are identically distributed or not.