Although the growth of longitudinal data archives is one of the most dramatic developments in the behavioural sciences, there has been a barrier to the effective use of these files due to a lack of understanding of the relation between research questions and archival data - until now. The authors of this volume illustrate how to use the model-fitting process to select and fit the right data set to a particular research problem. Beginning with an introduction to the general issues in working with archival data, the book takes the reader through steps in the recasting of data and question, using substantive examples from the life course, such as temporal patterns of physical and emotional health as well as pathways to retirement.