ABSTRACT
The measurement of change is critically important in psychology and the social sciences because when people acquire new skills, when they learn something new, when they grow intellectually and physically, when their attitudes and interests develop, they change in fundamental and interesting ways. It is only by being able to measure change over time accurately that we can map out critical time-dependent phenomena at the core of human development. Unfortunately, despite its obvious importance, there has been much controversy over the years about the measurement of change. In the past, influential methodologists have examined the technical properties of change measurement and convinced themselves, and everyone else, that it is impossible to measure change well. But recent developments demonstrate that not only can change be measured, but, with a little foresight and planning, it can be measured extremely well.
