Person-centered and variable-centered approaches to longitudinal data

As the number and scope of longitudinal investigations have expanded, so too have strategies for analyzing prospective data. Different analytic techniques are designed to answer different types of research questions. Person-centered approaches identify groups of individuals who share particular attributes or relations among attributes. They are well suited for addressing questions that concern group differences in patterns of development. Variable-centered approaches describe associations between variables. They are well suited for addressing questions that concern the relative contributions that predictor variables make to an outcome. This special issue includes conceptual essays and empirical reports designed to demonstrate the complementary strengths of these two different approaches. The articles illustrate how the integration of person-oriented and variable-oriented approaches can lead to a more complete understanding of the processes and patterns of human development.