This class-tested introduction emphasizes the relatedness of the models that builds a strong foundation of the basics to better prepare readers for the more advanced models to come. Organized by research design, the text emphasizes modeling decisions unique to longitudinal or repeated measures data. Examples with sample results sections emphasize the steps involved in reporting the model specification and the decision-making and interpretation processes. The website features the book's data sets, syntax and sample output for various programs, and exercises. Ideal for advanced students and researchers in the behavioral and social sciences, prerequisites include familiarity with GLM and SEM.