Developmental scientists are often interested in subgroups of people who share commonalities in aspects of development; these subgroups often cannot be captured directly but instead must be inferred from other information. Mixture models can be used in these situations. Two specific types of mixture models, latent profile transition analyses and…

Existing data sets can be an efficient, powerful, and readily available resource for addressing questions about developmental science. Many of the available databases contain hundreds of variables of interest to developmental psychologists, track participants longitudinally, and have representative samples. In this article, the authors discuss the…

The purpose of this paper is to discuss ways in which developmental psychology suffers from the lack of an appropriate technology of measurement and statistical analysis. The paper begins by noting that developmental psychology is the study of change; that individuals develop through a succession of "stages" which are separated by…