This article provides an introduction to the idiographic approach ("N = 1" research) in developmental psychology and an overview of methodological and statistical techniques employed to address the study of within-individual variability in development. Through a popularization of the idiographic approach and associated statistical…

During adolescence, friendship affiliations and groups provide companionship and social and emotional support, and they afford opportunities for intimate self-disclosure and reflection. Friendships often promote positive psychosocial development, but some youth learn and adopt antisocial attitudes and deviant behaviors through their friendships.…

This chapter discusses the "person approach" to studying developmental processes by focusing on the distinction and complementarity between this holistic-interactionistic framework and what has become designated as the variable approach. Particular attention is given to measurement models for use in the person approach. The discussion on the…