*Bestselling reference and text, now updated: 50% new material includes six new chapters and the only documentation for PROCESS v3. *Hayes is the developer of PROCESS, a free add-on for SPSS and SAS that takes the computational burden off the researcher. *Includes tips and advice, and carefully explains each step in an analysis using current, compelling data examples; e.g., studies of media influence, workplace dynamics, and attitudes toward disaster victims. *Helps readers understand the link between statistics and causality, as well as what the data is telling them. *Hayes conducts workshops worldwide and gets raves for his blog and discussion board; his website offers free PROCESS downloads plus data files for the book's examples.