Classification as a Tool for Research : Proceedings of the 11th IFCS Biennial Conference and 33rd Annual Conference of the Gesellschaft für Klassifikation e.V. Dresden March 13 18 2009 Plenaries Classification and Data Analysis: Classification Data Analysis Applications: Archeaology and Spatial Planning Bio Sciences Electronic Data and Web Finance and Banking Linguistics Marketing Music Science Quality Assurance and Engineering. Clustering and Classification Data Analysis Data Handling and Business Intelligence are research areas at the intersection of statistics mathematics computer science and artificial intelligence. They cover general methods and techniques that can be applied to a vast set of applications such as in business and economics marketing and finance engineering linguistics archaeology musicology biology and medical science. This volume contains the revised versions of selected papers presented during the 11th Biennial IFCS Conference and 33rd Annual Conference of the German Classification Society (Gesellschaft für Klassifikation GfKl). The conference was organized in cooperation with the International Federation of Classification Societies (IFCS) and was hosted by Dresden University of Technology Germany in March 2009.