Practical considerations in equating progress tests.

Progress testing offers a unique contribution to medical education assessment in that it provides a tool for monitoring examinees' growth over time and their progress toward graduation objectives. However, one of the most important psychometric requirements of progress testing has typically been neglected in past applications: scores across the time and test forms are not commonly placed on the same scale. Equating is a method used to achieve this property. This article discusses the basic principles of equating and the particular challenges posed by progress testing. A hybrid equating method, along with the details of a recent application, is presented as a potential solution, and alternate approaches to equating are discussed. It is hoped that future applications of progress testing will both utilize equating and demonstrate its value as a tool in medical education assessment.