The discussion here covers five articles that are linked in the sense that they all treat population invariance. This discussion of population invariance is a somewhat broader treatment of the subject than simply a discussion of these five articles. In particular, occasional reference is made to publications other than those in this issue. The…

This article discusses the five studies included in this issue. Each article addressed the same topic, population invariance of equating. They all used data from major standardized testing programs, and they all used essentially the same statistics to evaluate their results, namely, the root mean square difference and root expected mean square…

Current educational policy highlights the important role that assessment can play in improving education. State standards and the assessments that are aligned with them establish targets for learning and promote school accountability for helping all students succeed; at the same time, feedback from assessment results is expected to provide …