About

I joined the working group "Biometry in Molecular Medicine" (led by Prof. Anne-Laure Boulesteix) as a PhD student in June 2019. My research focuses on validation and over-optimism in the context of cluster analysis. I am a member of the Munich Center for Machine Learning.

I have a Master's Degree (M.Sc.) in Mathematics from the Ludwig-Maximilians-University Munich.

 Research Interests

• Cluster Analysis
• Validation and replication of research findings
• Researcher degrees of freedom and over-optimism
• Microbiome data

Publications

Submitted articles

• T. Ullmann, S. Peschel, P. Finger, C. L. Müller, A.-L. Boulesteix, 2022. Over-optimism in unsupervised microbiome analysis: Insights from network learning and clustering. bioRxiv preprint DOI: 10.1101/2022.06.24.497500
• B. Bischl, M. Binder, M. Lang, T. Pielok, J. Richter, S. Coors, J. Thomas, T. Ullmann, M. Becker, A.-L. Boulesteix, D. Deng, M. Lindauer, 2021. Hyperparameter Optimization: Foundations, Algorithms, Best Practices and Open Challenges. arXiv preprint arXiv:2107.05847

Peer-reviewed articles

• T. Ullmann, A. Beer, M. Hünemörder, T. Seidl, A.-L. Boulesteix, 2022. Over-optimistic evaluation and reporting of novel cluster algorithms: an illustrative study. Advances in Data Analysis and Classification DOI:10.1007/s11634-022-00496-5.
• M. König, T. Ullmann, B. Pastor-Villaescusa, R. Dalla-Pozza, S. Bohlig, A. Schmidt-Trucksäss, J. Pattathu, N.A. Haas, A. Jakob, 2022. KD Diagnosis Does Not Increase Cardiovascular Risk in Children According to Dynamic Intima–Media Roughness Measurements. Journal of Clinical Medicine 11(5): 1177.
  
• T. Ullmann, C. Hennig, A.-L. Boulesteix, 2021. Validation of cluster analysis results on validation data: A systematic framework. Wiley Interdisciplinary Reviews: Data Mining and Knowledge Discovery DOI: 10.1002/widm.1444.
• C. Stachl, Q. Au, R. Schoedel, S. D. Gosling, G. M. Harari, D. Buschek, S. T. Völkel, T. Schuwerk, M. Oldemeier, T. Ullmann, H. Hussmann, B. Bischl, M. Bühner, 2020. Predicting personality from patterns of behavior collected with smartphones. Proceedings of the National Academy of Sciences 117 (30): 17680-17687.