'Does the field need yet another book on longitudinal analysis? Absolutely! Packed with practical advice and hands-on instruction, here's a book dedicated to teaching and communicating, not impressing and obfuscating. With flair and style, Castilla provides step-by-step instructions for conducting longitudinal analysis, expertly motivated with carefully selected research examples. At long last, that rarest of entities: the demystifying methods book' - David B. Grusky, Professor of Sociology and Director of the Center for the Study of Poverty and Inequality, Stanford University. 'Castilla's introduction to longitudinal analysis is the most accessible text in this field. It is exceptional that it takes the reader from the most elementary concepts to quite advanced applications, including how to understand, evaluate and write research papers. If there are still changes to be made to the manuscript. I was somewhat in trouble by his distinction between qualitative and quantitative variables. I think the distinction in the headings and subheadings using discrete and continuous variables would be much better. 'Qualitative' is really confusing, since people than expect textual and historical kind of data' - Karl Ulrich Mayer, Professor and Chair, Sociology Department and Co-Director, Center for Research on Inequalities and the Life Course (CIQLE), Yale University. 'Castilla has written an excellent, accessible, and highly useful book on longitudinal data analysis. He covers what these methods can do, the use of relevant software, how one should design studies, and provides insightful applications. I will use it in courses. An excellent contribution' - Trond Petersen, Professor and Chair, Department of Sociology, University of California, Berkeley.