The book "Intensive Longitudinal Methods" offers a comprehensive and practical guide to conducting intensive longitudinal studies with individuals, dyads, or groups. It is aimed at researchers who wish to investigate social, psychological, and physiological processes in everyday life. By employing methods such as diary and experience sampling, readers are equipped to address relevant research questions. The work includes a variety of illustrative, well-developed research examples supported by datasets. The content covers, among other things, the selection of appropriate designs for specific research questions, the application of multilevel models to within-subject designs, and the modeling of change processes. Additionally, strategies for ensuring statistical power and assessing reliability within subjects are discussed. At the end of each chapter, examples are provided that demonstrate effective ways to present study results for publication.