Measurement and the Study of Change

Many constructs developmental scientists study cannot be directly observed. In such cases, scales are created that reflect the construct of interest. Observed behaviors are taken as manifestations of an unobserved common cause. As crucial as measurement is to understanding many psychological phenomenon, it is perhaps even more important when the goal of research is to understand how a construct changes over time. In this article we review several approaches to measurement, note features of latent variable measurement models which are ideally suited to the study of change, describe a hypothetical example, and conclude with a discussion of measurement and development.