This volume focuses on methods of data treatment, emphasising the importance of careful matching of methodology to the substantive problem under consideration. It deals particularly with concepts of stability and change which are central to personality and developmental research. Contributions to this volume explore the methodology and scope of life span studies in a varity of contexts, including intellectual and cognitive development, transitions such as that from childhood to early adult life, social mobility, behavioural genetics, and psychological disorder, particularly depression. A valuable reference for a wide range of interests in developmental psychology, social and behavioural science, psychiatry, epidemiology and statistics.