The book provides a systematic introduction to cluster analysis methods used in various disciplines, such as determining different lifestyles and consumption patterns or value orientation types. The third edition has been expanded to include a collection of examples from research practice, a comprehensive listing and description of criteria for good classification. It now also considers distance measures for longitudinal data, the treatment of missing values using cluster analysis, and validation indices. Additionally, a significant enhancement to the K-Means method is the inclusion of the multiple random starting values approach, along with generalizations that utilize other distance functions and location parameters. Model-based methods, which allow for the modeling of complex cluster models, have been given considerably more space.