Rater effects, or raters' tendencies to assign ratings to performances that are different from the ratings that the performances warranted, are well documented in rater-mediated assessments across a variety of disciplines. In many real-data studies of rater effects, researchers have reported that raters exhibit more than one effect, such as a…

The number of performance assessments continues to increase around the world, and it is important to explore new methods for evaluating the quality of ratings obtained from raters. This study describes an unfolding model for examining rater accuracy. Accuracy is defined as the difference between observed and expert ratings. Dichotomous accuracy…

In a study involving eight judges, analysis with the FACETS model provides evidence that judges grade differently, whether or not scores correlate well. This outcome suggests that adjustments for differences among judges should be made before student measures are estimated to produce reproducible decisions. (SLD)