"This wonderful book is an absolute must for researchers who are studying positive psychology, and will do much to advance the sophistication of this field. Other scientists, however, will also profit from the excellent treatment of advanced issues by experts in the field, with topics such as hierarchical linear modeling, experience-sampling, dynamic factor analysis and systems analysis, spectral analysis, and latent growth curve models. A bonus is the inclusion of chapters on topics such as hardiness, character, and wisdom that integrate conceptual and methodological issues. This is a superb reference on advanced research design."--Ed Diener, Alumni Distinguished Professor of Psychology, University of Illinois at Urbana-Champaign, and Editor, Perspectives on Psychological Science, and Journal of Happiness Studies