Mixed-format assessments are increasingly being used in large scale standardized assessments to measure a continuum of skills ranging from basic recall to higher order thinking skills. These assessments are usually comprised of a combination of (a) multiple-choice items which can be efficiently scored, have stable psychometric properties, and…

Dorans and Holland (2000) and von Davier, Holland, and Thayer (2003) introduced measures of the degree to which an observed-score equating function is sensitive to the population on which it is computed. This article extends the findings of Dorans and Holland and of von Davier et al. to item response theory (IRT) true-score equating methods that…

An increasingly popular test format allows examinees to choose the items they will answer from among a larger set. When examinee choice is allowed fairness requires that the different test forms thus formed be equated for their possible differential difficulty. For this equating to be possible it is necessary to know how well examinees would have…