Item response theory (IRT) is having a major impact on the field of testing. This special issue presents an introduction and seven papers concerning developments in IRT applications. Some important IRT research being conducted outside the United States is highlighted. (SLD)

This study utilized a straightforward system of crediting successes and assigning failures to items not administered during computerized adaptive testing (CAT) to determine if the data yielded by CAT could be used to monitor item calibrations over time. (Author/LMO)

This paper describes a computer program in Microsoft BASIC which selects and administers test items from a small item bank. The level of the difficulty of the item selected depends on the test taker's previous response. This adaptive system is based on the Rasch model. The Rasch model uses a unit of measurement based on the logarithm of the…

ASCAL is a microcomputer-based program for calibrating items according to the three-parameter logistic model of item response theory. It uses a modified multivariate Newton-Raphson procedure for estimating item parameters. This study evaluated this procedure using Monte Carlo Simulation Techniques. The current version of ASCAL was then compared to…

Three questions concerning the Binary Search Method (BSM) of computerized adaptive testing were studied: (1) whether it provided a reliable and valid estimation of examinee ability; (2) its effect on examinee attitudes toward computerized adaptive testing and conventional paper-and-pencil testing; and (3) the relationship between item response…