This booklet grew out of a half-day class on equating that author Samuel Livingston teaches for new statistical staff at Educational Testing Service (ETS). The class is a nonmathematical introduction to the topic, emphasizing conceptual understanding and practical applications. The class consists of illustrated lectures, interspersed with…

In the equating literature, a recurring concern is that equating functions that utilize a single anchor to account for examinee groups' nonequivalence are biased when the groups are extremely different and/or when the anchor only weakly measures what the tests measure. Several proposals have been made to address this equating bias by incorporating…

As is the case for any statistical model, a multidimensional latent growth model comes with certain requirements with respect to the data collection design. In order to measure growth, repeated measurements of the same set of individuals are required. Furthermore, the data collection design should be specified such that no individual is given the…