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Prof. Dr. Ulf Brefeld

21335 Lüneburg, Universitätsallee 1, C4.311
Fon +49.4131.677-1663, ulf.brefeld@leuphana.de
Professor, Professorship of Information Systems, in particular Machine Learning

Table of contents for this page

Vita

I am a professor for Machine Learning at Leuphana Universität Lüneburg. Prior to joining Leuphana, I was a joint professor for Knowledge Mining & Assessment at TU Darmstadt and the German Institute for Educational Research (DIPF), Frankfurt am Main. Before, I led the Recommender Systems group at Zalando SE and worked on machine learning at Universität Bonn, Yahoo! Research Barcelona, Technische Universität Berlin, Max Planck Institute for Computer Science in Saarbrücken, and at Humboldt-Universität zu Berlin. I received a Diploma in Computer Science in 2003 from Technische Universität Berlin and a Ph.D. (Dr. rer. nat.) in 2008 from Humboldt-Universität zu Berlin. I am interested in statistical machine learning and data mining. ML3 homepage

Projects

  1. Verbundprojekt: Anonymisierung und Synthese von Bewegungsdaten in Web und Smart- Cities - SynTrace -
    Ulf Brefeld (Project manager, academic)
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    Project: Research

  2. Adaptive Learning for Economic Education
    Ulf Brefeld (Project manager, academic) , Kai Neubauer (Project manager, academic)
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    Project: Research

  3. Verbundprojekt: Anonymisierung und Synthese von Clickpfaden und Verhalten im Web
    Ulf Brefeld (Project manager, academic) , Moritz Hauke Wohlstein (Project staff)
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    Project: Research

  4. Information Technology and Education in Support of Digital Citizenship
    Valéria Quadros dos Reis (Project manager, academic) , Ulf Brefeld (Project manager, academic)
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    Project: Research

  5. Memory Path
    Ulf Brefeld (Project manager, academic)
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    Project: Other

View all projects

Publications

Books and anthologies

  1. Machine Learning and Data Mining for Sports Analytics: 11th International Workshop, MLSA 2024, Vilnius, Lithuania, September 9, 2024, Revised Selected Papers
    Ulf Brefeld (Editor) , Jesse Davis (Editor) , Jan Van Haaren (Editor) , Albrecht Zimmermann (Editor) , 2025 Cham , 119 p.

    Research output: Books and anthologies › Conference proceedings › Research

  2. Machine Learning and Knowledge Discovery in Databases: European Conference, ECML PKDD 2019, Würzburg, Germany, September 16–20, 2019, Proceedings, Part I
    Ulf Brefeld (Editor) , Elisa Fromont (Editor) , Andreas Hotho (Editor) , Arno Knobbe (Editor) , Marloes Maathuis (Editor) , Céline Robardet (Editor) , 2020 Cham , 766 p.

    Research output: Books and anthologies › Conference proceedings › Research

  3. Machine Learning and Knowledge Discovery in Databases: European Conference, ECML PKDD 2019, Würzburg, Germany, September 16–20, 2019, Proceedings, Part II
    Ulf Brefeld (Editor) , Elisa Fromont (Editor) , Andreas Hotho (Editor) , Arno Knobbe (Editor) , Marloes Maathuis (Editor) , Céline Robardet (Editor) , 2020 Cham , 732 p.

    Research output: Books and anthologies › Conference proceedings › Research

  4. Machine Learning and Knowledge Discovery in Databases: European Conference, ECML PKDD 2019, Würzburg, Germany, September 16–20, 2019, Proceedings, Part III
    Ulf Brefeld (Editor) , Elisa Fromont (Editor) , Andreas Hotho (Editor) , Arno Knobbe (Editor) , Marloes Maathuis (Editor) , Céline Robardet (Editor) , 2020 Cham , 804 p.

    Research output: Books and anthologies › Conference proceedings › Research

  5. Machine Learning and Data Mining for Sports Analytics: 7th International Workshop, MLSA 2020, Co-located with ECML/PKDD 2020, Ghent, Belgium, September 14–18, 2020, Proceedings
    Ulf Brefeld (Editor) , Jesse Davis (Editor) , Jan van Haaren (Editor) , Albrecht Zimmermann (Editor) , 2020 Cham , 146 p.

    Research output: Books and anthologies › Conference proceedings › Research

View all publications

Journal contributions

  1. Principled Transformers for Predictive Performance in Knowledge Tracing
    Kai Neubauer (Author) , Ulf Brefeld (Author) , Yannick Rudolph (Author) , 01.01.2026 , in: Journal of Educational Data Mining, 18, 1 , p. 89-112 , 24 p.

    Research output: Journal contributions › Journal articles › Research › peer-review

  2. Joint Item Response Models for Manual and Automatic Scores on Open-Ended Test Items
    Daniel Bengs (Author) , Ulf Brefeld (Author) , Ulf Kroehne (Author) , Fabian Zehner (Author) , 01.09.2025 , in: Psychometrika, 90, 4 , p. 1346-1367 , 22 p.

    Research output: Journal contributions › Journal articles › Research › peer-review

  3. The promise and challenges of computer mouse trajectories in DMHIs – A feasibility study on pre-treatment dropout predictions
    Kirsten Zantvoort (Author) , Pontus Bjurner (Author) , Marie Bendix (Author) , Ulf Brefeld (Author) , Burkhardt Funk (Author) , Viktor Kaldo (Author) , Jennifer Matthiesen (Author) , 01.06.2025 , in: Internet Interventions, 40 , 7 p.

    Research output: Journal contributions › Journal articles › Research › peer-review

  4. Masked autoencoder for multiagent trajectories
    Ulf Brefeld (Author) , Yannick Rudolph (Author) , 01.02.2025 , in: Machine Learning, 114, 2 , 18 p.

    Research output: Journal contributions › Journal articles › Research › peer-review

  5. Interactive sequential generative models for team sports
    Moritz Cordes (Author) , Ulf Brefeld (Author) , Dennis Fassmeyer (Author) , 01.02.2025 , in: Machine Learning, 114, 2 , 15 p.

    Research output: Journal contributions › Journal articles › Research › peer-review

View all publications

Contributions to collected editions/anthologies

  1. Self-improvement for Computerized Adaptive Testing
    Kai Neubauer (Author) , Ulf Brefeld (Author) , Yannick Rudolph (Author) , 01.01.2026 Cham , p. 70-86 , 17 p.

    Research output: Contributions to collected editions/anthologies › Article in conference proceedings › Research › peer-review

  2. Studying properties of water data using manifold-aware anomaly detectors
    Tino Paulsen (Author) , Ulf Brefeld (Author) , 23.04.2024

    Research output: Contributions to collected editions/anthologies › Article in conference proceedings › Research › peer-review

  3. Masked Autoencoder Pretraining for Event Classification in Elite Soccer
    Ulf Brefeld (Author) , Yannick Rudolph (Author) , 26.02.2024 Cham , p. 24-35 , 12 p.

    Research output: Contributions to collected editions/anthologies › Article in conference proceedings › Research › peer-review

  4. Hands in Focus: Sign Language Recognition Via Top-Down Attention
    Noha Sarhan (Author) , Christian Wilms (Author) , Vanessa Closius (Author) , Ulf Brefeld (Author) , Simone Frintrop (Author) , 08.10.2023 Piscataway , p. 2555-2559 , 5 p.

    Research output: Contributions to collected editions/anthologies › Article in conference proceedings › Research › peer-review

  5. Exploring the Poincaré Ellipsis
    Tino Paulsen (Author) , Ulf Brefeld (Author) , Samuel Fadel (Author) , 01.09.2023

    Research output: Contributions to collected editions/anthologies › Article in conference proceedings › Research › peer-review

View all publications

Activities

  1. Self-improvement for Computerized Adaptive Testing
    Kai Neubauer (Speaker) , Ulf Brefeld (Coauthor) , Yannick Rudolph (Speaker)

    Activity: Conference Presentations › Research

  2. Masked Autoencoder Pretraining for Event Classification in Elite Soccer
    Ulf Brefeld (Coauthor) , Yannick Rudolph (Speaker)

    Activity: talk or presentation in privat or public events › Research

  3. Data-efficient Pattern Detection in Elite Soccer
    Ulf Brefeld (Coauthor) , Yannick Rudolph (Speaker) , Dennis Faßmeyer (Coauthor)

    Activity: Conference Presentations › Research

  4. Modeling Conditional Dependencies in Multiagent Trajectories
    Ulf Brefeld (Coauthor) , Yannick Rudolph (Speaker)

    Activity: Presentations (poster etc.) › Research

  5. Detection of tactical patterns using semi-supervised graph neural networks
    Gabriel Anzer (Speaker) , Pascal Bauer (Speaker) , Ulf Brefeld (Speaker) , Dennis Faßmeyer (Speaker)

    Activity: Conference Presentations › Research

View all activities

Press / Media

  1. Data Science: Lern- und Ausbildungsinhalte
    1 Media contribution

    Press/Media: Press/Media

View all press/media coverage

Courses

Development of an AI level guide for courses in complementary studies
Ulf Brefeld
Studierende können vor der Kurswahl häufig schwer einschätzen, welche Vorkenntnisse in Lehrveranstaltungen zu KI-Themen tatsächlich vorausgesetzt werden. Dieses Seminar widmet sich der Erstellung eines transparenten und verständlichen KI-Niveau-Guides, der Lehrveranstaltungen hinsichtlich ihres Anspruchsniveaus einordnet und so eine passgenauere Kurswahl ermöglicht. Ziel ist es, Über- und Unterforderung in Lehrveranstaltungen zu vermeiden. Zunächst analysieren die Studierenden bestehende Kompetenzmodelle (z.B. das UNESCO AI Competency Framework For Students) und diskutieren deren Vor- und Nachteile. Auf Grundlage dieser Kenntnisse entwickeln die Studierenden Kriterien und Formate für ihren eigenen KI-Niveau-Guide. Die entwickelten KI-Niveau-Guides werden durch gegenseitiges Feedback weiter optimiert.
Next appointment:
Wednesday, 2026-10-14 at 10:15
Room: C 12.112 Seminarraum
Machine Learning Lab
Ulf Brefeld
Address a learning task in a data-driven fashion. After reviewing related work, you'll formalize the problem, derive an appropriate method to solve it, implement the method, define an experimental setup and identify relevant baselines and empirically evaluate your approach. The learning task can be arbitrarily defined. We provide fallback problems but bringing your own idea(s) and/or data is more than welcome! The final report may have the form of a research paper. We'll have milestones where progress is reported in short presentations.
Next appointment:
Thursday, 2026-10-15 at 14:15
Room: C 12.108 Seminarraum
Research Colloquium Business Informatics & Data Science
Olga Abramova, Ulf Brefeld, Paul Drews, Burkhardt Funk, Peter Niemeyer, Kathrin Padberg-Gehle, Ricardo Usbeck
The Research Colloquium at the Institute for Information Systems (IIS) at Leuphana University is a dynamic and interdisciplinary platform for scholarly exchange, critical dialogue, and academic networking focused on PhD students in and around Data Science and AI. Designed to foster a vibrant research culture, the colloquium brings together faculty, researchers, doctoral candidates, and external guests to discuss current topics in the field of information systems and beyond.

Our colloquium features a diverse set of formats:

* Research Talks: IIS faculty and doctoral researchers present ongoing projects and recent findings, receiving constructive feedback in a collaborative environment.

* Invited Expert Lectures: Renowned national and international scholars are invited to share cutting-edge research and theoretical insights, offering new perspectives and fostering academic exchange.

* Startup & Industry Talks: Entrepreneurs and professionals from startups and established companies discuss real-world challenges and innovations at the intersection of business and technology, providing practical insights and networking opportunities.

* Interdisciplinary Dialogues: The colloquium also opens space for collaborative sessions across disciplines, reflecting the integrative and transdisciplinary mission of Leuphana University.

Open to members of the university and interested guests, the IIS Research Colloquium serves as an essential forum for inspiration, collaboration, and advancing impactful research.
Next appointment:
Lectures for this semester ended.
Sports Analytics Seminar
Ulf Brefeld
Sports Analytics deals with player evaluation, performance prediction, match strategy and tactics and the impact of data-driven decision-making. The use of machine learning and data mining techniques has opened up new opportunities for Sports Analytics researchers and practitioners.
Next appointment:
Tuesday, 2026-10-13 at 14:15
Room: C 7.319 Seminarraum
Statistics for Computer Scientists
Ulf Brefeld
• Grundlagen Analysis
• Differential- und Integralrechnung
• Grundlagen Statistik
• Einführung in die Wahrscheinlichkeitstheorie
• Zufallsvariablen und Wahrscheinlichkeitsverteilungen
• Parametertests
• Konfidenzintervalle
• Hypothesentests
Next appointment:
Thursday, 2026-10-15 at 10:15
Room: W HS 4
Statistics for Computer Scientists - Group A
Ulf Brefeld, Soham Majumder
- Basics of Analysis
- Differential and integral calculus
- Fundamentals of statistics
- Introduction to probability theory
- Random variables and probability distributions
- Parameter tests
- Confidence intervals
- Hypothesis tests
Next appointment:
Tuesday, 2026-10-13 at 10:15
Room: C 14.006 Seminarraum
Statistics for Computer Scientists - Group B
Ulf Brefeld, Shirley Metz
- Basics of Analysis
- Differential and integral calculus
- Fundamentals of statistics
- Introduction to probability theory
- Random variables and probability distributions
- Parameter tests
- Confidence intervals
- Hypothesis tests
Next appointment:
Tuesday, 2026-10-13 at 10:15
Room: C 9.102 Seminarraum
Statistics for Computer Scientists - Group C
Ulf Brefeld, Soham Majumder
- Basics of Analysis
- Differential and integral calculus
- Fundamentals of statistics
- Introduction to probability theory
- Random variables and probability distributions
- Parameter tests
- Confidence intervals
- Hypothesis tests
Next appointment:
Tuesday, 2026-10-13 at 14:15
Room: C 12.107 Seminarraum
Statistics for Computer Scientists - Group D
Ulf Brefeld, Shirley Metz
- Basics of Analysis
- Differential and integral calculus
- Fundamentals of statistics
- Introduction to probability theory
- Random variables and probability distributions
- Parameter tests
- Confidence intervals
- Hypothesis tests
Next appointment:
Tuesday, 2026-10-13 at 14:15
Room: C 12.001 Seminarraum