Events such as curriculum changes or practice effects can lead to item parameter drift (IPD) in computer adaptive testing (CAT). The current investigation introduced a point- and weight-adjusted D[superscript 2] method for IPD detection for use in a CAT environment when items are suspected of drifting across test administrations. Type I error and…

In elementary books on applied statistics (e.g., Siegel, 1988; Agresti, 1990) and books on research methodology in psychology and personality assessment (e.g., Aiken, 1999), it is often suggested that the choice of a statistical test and the choice of statistical operations should be determined by the level of measurement of the data. Although…

"Diagnostic classification models" (DCM) are frequently promoted by psychometricians as important modelling alternatives for analyzing response data in situations where multivariate classifications of respondents are made on the basis of multiple postulated latent skills. In this review paper, a definitional boundary of the space of DCM…