Our long-time colleague Dr. Daniel Kottke left the University of Kassel on 01.12.2022 and now continues his career. During his research, he focused on active learning that is used to optimize training processes in machine learning by incorporating annotations from experts. This resulted in his doctoral thesis that is titled: "A Holistic Decision-Theoretic Framework for Pool-Based Active Learning." His broad interests lead to initiating the Smart Data Lab and the I²OTHACK. We are very grateful to Dr. Kottke for the excellent work he has done and look forward to staying in touch with him on a friendly and also on a scientific level. We wish him all the best for the future!