When dealing with missing responses, two types of omissions can be discerned: items can be skipped or not reached by the test taker. When the occurrence of these omissions is related to the proficiency process the missingness is nonignorable. The purpose of this article is to present a tree-based IRT framework for modeling responses and omissions…

Discusses the need for educational change and ways to achieve it. Topics include problems with testing, the importance of learning by doing, the lack of Internet's educational value, and the possibilities of using computer software to create real-life simulations for students to learn by doing and to design new curricula. (LRW)

In providing an alternative view to the previous article by Ward (TM 508 880), the author notes problems associated with adaptive testing, diagnostic testing, testing embedded in instruction, and testing through simulations. (BW)

The effects of a multidimensional latent trait space on estimation of item and person parameters by the computer program LOGIST are examined. Several item pools were simulated that ranged from truly unidimensional to an inconsequential general latent trait. Item pools with intermediate levels of prepotency of the general latent trait were also…