Designed for advanced courses in psychology and educational psychology, this systematic introduction to statistics and experimental design adheres stringently to basic probability theory and principles from mathematical statistics. The fifth edition, revised and updated, retains the reliable structure and scrupulous attention to accuracy that has made this text a classic in the field. Features: * Places solutions to half of the problems in Appendix G. The remainder are in the Instructors Manual. * Integrates material on set theories in appendices. * Problem sections now have practice problems with explanations. Students therefore see solutions worked through before they attempt problems on their own. * Udpates material on meta-analysis.