The textbook explains the execution and interpretation of classical regression analyses using the OLS method and logistic regression analyses using the ML method. The text particularly focuses on verifying the prerequisites for regression estimates. It also addresses typical fallacies and frequently encountered misinterpretations, including those related to coefficient of determination, standardized regression coefficients, and centered effects. Additionally, advanced methods such as power analyses, regressions with dummy variables, and model estimates with moderator and mediator variables are discussed. The presentation is practice-oriented, with all methods illustrated through examples, including the SPSS instructions necessary for practical application. New in the fifth edition are, among other things, regression analysis with missing values.