Members and Guests

Table of Contents

Current Members

Researchers

Currently the group hosts the following researchers:

Permanent staff

  • Dunja Šešelja (permanent student, aka full professor, Wasserstraße 221, office 4/202)

    dunja.jpg Dunja is a full professor working in social epistemology and philosophy of science at the Institute II for Philosophy at Ruhr University Bochum. She serves as a co-editor in chief of the European Journal for Philosophy of Science. Her research topics include formal modeling of scientific inquiry (with focus on agent-based modeling), scientific disagreements and controversies, pursuit-worthiness of scientific theories, and integrated history and philosophy of science. Find more information on her academia page.


  • Christian Straßer (permanent student aka full professor, Wasserstraße 221, office 4/401)

    pass2.png Christian is a full professor of Logic in Philosophy and Artificial Intelligence at the Institute for Philosophy II at Ruhr University Bochum. He is specialized in non-monotonic logics, defeasible reasoning, argumentation, deontic and adaptive logics. He is interested in utilizing formal methods (such as logical or computational methods) in philosophy. Beyond logic his research interests spread into the philosophy of science and social epistemology. You find more information on him here and his CV here (and a pdf here).


  • Prof. Dr. Dr. Cali (Hoomanologist)

    cali.png The –without doubt– most prominent and cheerful member of the group is the Hoomanologist Cali, specialized for Hooman intelligence and well-known for his books “How to train the hooman. The limitations of the hooman mind.” While working in our group he also got interested in logic, see his latest book “My barks don’t lie. Semantic paradoxes as a trademark of Hooman language.” Yes, we can learn a lot from him …

Doctoral- and Post-Doctoral researchers

  • Matteo Cerasa (PhD student, Ruhr-University Bochum)

    matteo-cerasa.jpg Matteo’s work is at the intersection of Bayesian Epistemology and Decision Theory, with a focus on formal models of Awareness Growth (changes in the possibilities space) and Transformative Experiences (learning ’what it is like’ and changes in fundamental preferences). For this research, he is jointly supervised by Christian in the Reasoning, Rationality, and Science group and by Peter Brössel in the RTG Situated Cognition.

  • Matteo Michelini (Cotutelle PhD student, TU Eindhoven and Ruhr-University Bochum)

    matteo-michelini.jpg Matteo is a cotutelle PhD student of TU Eindhoven and Ruhr University Bochum. He works with agent-based models in the areas of social epistemology and philosophy of science.
    Matteo is jointly supervised by Dunja and Wybo Houkes.


  • Luca Redondi (PhD, Wasserstraße, office 4/422)

    luca.jpeg Luca has a background in ethics with a focus on Kant and is especially interested in deontic logic. He works on applications of deontic logic and explanation in bioethics within the LoDEx project on Logical Methods for Deontic Explanation. Luca is supervised by Christian and Leon Van der Torre (Luxembourg).


  • Minkyung Wang (PostDoc, Wasserstraße 221, office 4/403)

    minkyung.jpg Minkyung is a postdoctoral researcher in Logic in Philosophy and Artificial Intelligence. Her current research focuses on integrating logical and probabilistic reasoning, which is addressed in formal epistemology, social epistemology, and formal argumentation. As a mathematical philosopher, she is keen on using formal methods to solve philosophical problems, particularly those related to epistemology, decision theory, and ethics. Her webpage is here.


  • Soong Yoo (PhD student, Wasserstraße 221, office 4/423)

    soong-yoo.jpg Should epistemic workers of the world unite? There are some thoughts or decision we would make only when hanging around with friends, colleagues, and strangers. Same for people doing cognitive tasks for their living. Soong is working with agent-based-models in hope to see how computer simulations would predict and suggest a better conveyor belt of knowledge production.
    Soong is jointly supervised by Dunja and Christian.

Administration

  • Christiane Dahl (admin, Building GA 04/42, Mondays at Wasserstraße 4/402)

    letterbox_400__trans_18c974cb771c27d50886ec64e546607f_letterbox_650__trans_74c76e999bc593d614f4b18f45adddd4_foto_cd.jpg Christiane is running the offices of Markus Werning, Kristina Liefke, Dunja, and Christian.





Student Staff

  • Jessica Krumus

    jessica.jpg Jessica is a Bachelor student in Philosophy and Biology. She has a special interest in logic and metaphysics. After tutoring for the Logic introductory lecture, she started as a student research assistent for Dunja and Christian.

  • Tom-Felix Berger

    tomfelix.jpg Tom-Felix is a Master’s student in philosophy at the Ruhr University Bochum and a Master’s student in data science at Fernuniversität Hagen. He works as a student assistant for Christian and Dunja and adds content to the LoDEx website. His main research interest is in the evolution of moral thought in humans, which he investigates using formal tools such as agent-based modelling and game theory.

Guests

We frequently host guests researchers, from experienced scholars to Master and PhD-students. This often leads to collaborations and joint publications. If you are excited about the research we’re doing and/or if you think that your research connects nicely to ours, please feel free to get in touch!

Current Guests

  • Piero Avitabile (IMT, Lucca)

    piero-picture.jpg Piero is a PhD student from IMT School for Advanced Studies in Lucca (Italy), supervised by Gustavo Cevolani. His research interests lie in the epistemology of expertise and informal argumentation theory, specifically exploring the normative conditions for reasonable discourse between scientific experts and laypeople.

Previous guests (PhD and Master students)

  • Edoardo Baccini: TODO

  • Zheng Zhou (PhD student, Beijing Normal University)

    zheng.jpg Zheng is a PhD student from the School of Philosophy at Beijing Normal University. Since December 2023, he has been conducting a one-year visit in Bochum. Zheng’s interests primarily lie in the application of formal argumentation in normative reasoning and deontic explanation. His email is zhouzhenglogic@mail.bnu.edu.cn.

    Outcome
    1. Zheng Zhou, Christian Straßer and Kees Van Berkel,
      Hypothesis-Driven Disjunctive Reasoning in Logical Argumentation,
      Forthcoming in the Proceedings of LORI 2025
    2. Kees van Berkel, Christian Straßer, and Zheng Zhou,
      Towards an Argumentative Unification of Default Reasoning,
      Frontiers in Artificial Intelligence and Applications (COMMA), Vol. 388, 313-324
  • Javier Osorio Mancilla, Autonomous University of Madrid: Javier will stay with us from January 15-30 2025. He gave a talk for our MA and PhD students.
    Outcome
    • two research papers under review

  • Martin Justin (Master Student, University of Ljubljana)

    martin-justin.jpg Martin is a master’s student of philosophy at University of Ljubljana. As an exchange student at RUB, he is working with Dunja on his thesis about disagreement in scientific communities.

    Outcome
    • one research paper under review
    • new ideas are baking in the oven

Previous Guests (PostDocs and Professors)

  • Ofer Arieli (Professor of Computer Science at the School of Computer Science, The Academic College of Tel-Aviv)

    ofer.jpg Ofer visits our group frequently, last time for one month until the 10th of June 2024

    Outcome
    By now Ofer and Christian have 10 years of research collaborations leading to \( >20 \) publications. One of our next steps is to write a book on our approach to logical argumentation that runs under the name “sequent-based argumentation”.

  • Badran Raddaoui (Wasserstraße 221, office 4/403, Associate Professor, Telecom SudParis, Polytechnic Institute of Paris).

    badran.png Badran is spending his sabbatical as a guest in Bochum. This has been a great opportunity for Christian to learn about inconsistency measures!

    Outcome
    1. Christian Straßer, Badran Raddaoui and Said Jabbour,
      Decomposing Inconsistencies: Marginal Contributions and Pooling Techniques,
      Forthcoming in the Proceedings of IJCAI 2025
    2. Ofer Arieli, Kees van Berkel, Badran Raddaoui and Christian Straßer,
      Deontic Reasoning based on Inconsistency Measures,
      Forthcoming in Proceedings of KR’2024.
    3. Said Jabbour, Badran Raddaoui, Christian Straßer,
      Towards a Principle-based Framework for Assessing the Contribution of Formulas on the Conflicts of Knowledge Bases,
      , Proceedings of the Thirty-Third International Joint conference on Artificial Intelligence, 3541-3548, 2024.
    4. Said Jabbour, Badran Raddaoui and Christian Straßer,
      A Comparative Study of Ranking Formulas based on Consistency,
      accepted for publication in IJCAI 2023 (15% acceptance rate)
    5. Jesse Heyninck, Badran Raddaoui and Christian Straßer,
      Ranking-based Argumentation Semantics applied to Logical Argumentation,
      accepted for publication in IJCAI 2023 (15% acceptance rate)
  • Leon van der Torre (Luxembourg) and Reka Markovich (Luxembourg) visited us for a week in March 2023.
    Outcome
    • Kees van Berkel, Reka Markovich, Christian Straßer, Leon van der Torre,
      Arguing About Choosing a Normative System: Conflict of Laws,
      Legal Knowledge and Information Systems (JURIX 2023), p. 73–82, 2023

Previous Staff

Previous PostDocs

  • Eliot Watkins (PostDoc, Wasserstraße, office 4/403)

    eliot.jpg Eliot Watkins joined the research group as a postdoc in 2024 after completing a PhD in Philosophy at MIT. His research focuses on the nature of reasons and the semantics of normative natural language. Examples of some of the more unusual positions defended by Eliot in recent work include the claim that reasons to eat ham sandwiches needn’t be reasons to eat sandwiches, and the claim that there are normative reasons for smoke detectors to behave in some ways and not others. At Bochum, Eliot is working as a part of LoDEX (Logical Methods of Deontic Explanation) — a WEAVE-funded collaboration between Ruhr-University Bochum, TU Vienna and the University of Luxembourg. You can find out more about his research here.


  • Kees van Berkel (Assistant Prof. TU Vienna, tenured)

    kees.png Kees is a PostDoc in the Reasoning, Rationality & Science group. You find his webpage here. He works on logical methods for normative reasoning. This includes methods from modal logic, nonmotonic logic, proof theory, and formal argumentation. He is working together with Christian on formal explanation of reasoning with normative systems. Kees is furthermore interested in the metaethical principle of `ought implies can’ (both from a philosophical and logical point of view), and the philosophy of practical reasoning.

    Outcome
    We have an ongoing research collaboration on logical argumentation and its use in deontic reasoning. We developed the DAC system for this, based on sequent-based argumentation and an explicit representation of norms (resp. defaults) in the object language. Here are our papers so far.
    1. Kees van Berkel and Christian Straßer,
      Reasoning With and About Normative Conflicts,
      forthcoming in the Proceedings of DEON 2025
    2. Zheng Zhou, Christian Straßer and Kees Van Berkel,
      Hypothesis-Driven Disjunctive Reasoning in Logical Argumentation,
      Forthcoming in the Proceedings of LORI 2025
    3. Kees van Berkel and Christian Straßer
      A Tutorial in Proof-Theoretic Approaches to Logical Argumentation
      forthcoming in Proceedings of the Reasoning Web Summer School 2023 (Springer Lecture Notes in Computer Science)
    4. Kees van Berkel and Christian Straßer
      Towards Deontic Explanations Through Dialogue
      Proceedings of Argumentation for eXplainable AI 2024 (ArgXAI)
    5. Ofer Arieli, Kees van Berkel, Badran Raddaoui and Christian Straßer,
      Deontic Reasoning based on Inconsistency Measures,
      Forthcoming in Proceedings of KR’2024.
    6. Kees van Berkel, Christian Straßer, and Zheng Zhou,
      Towards an Argumentative Unification of Default Reasoning,
      Frontiers in Artificial Intelligence and Applications (COMMA), Vol. 388, 313-324
    7. Ofer Arieli, Kees van Berkel, Christian Straßer,
      Defeasible Normative Reasoning: A Proof-Theoretic Integration of Logical Argumentation,
      Forthcoming, AAAI 2024.
    8. Kees van Berkel, Reka Markovich, Christian Straßer, Leon van der Torre,
      Arguing About Choosing a Normative System: Conflict of Laws,
      Legal Knowledge and Information Systems (JURIX 2023), p. 73–82, 2023
    9. Kees van Berkel and Christian Straßer,
      Reasoning with and About Norms in Logical Argumentation,
      Proceedings of COMMA 2022.
    10. Ofer Arieli, Kees van Berkel and Christian Straßer,
      Annotated Sequent Calculi for Paraconsistent Reasoning and Their Relations to Logical Argumentation,
      Proceedings of IJCAI 2022 (acceptance rate, 15%)

Previous Student Staff

  • Lisa Michajlova

    lisa.jpg Lisa is now finishing her Bachelor of Science in Mathematics with minor in Philosophy. She currently works as a student assistant with Christian on Probabilistic Argumentation theory. She studies the Probabilistic Framework by Haenni and investigates argument strength defined for example by Pfeifer. Lisa loves playing sports including table tennis and chess.

    Outcome
    • Christian Straßer and Lisa Michajlova,
      Evaluating and Selecting Arguments in the Context of Higher Order Uncertainty,
      Frontiers in Artificial Intelligence, Vol. 6


Associate Members

  • Daniel Frey (Currenta, Leverkusen)
    Daniel frequently collaborates with us on agent-based models. He is equally interested in the implementation side of things (e.g., NetLogo) and the conceptual considerations underlying formal models. His master thesis offers an investigation into Kevin Zollman’s notion of transient diversity.


  • Badran Raddaoui (Associate Professor, Telecom SudParis, Polytechnic Institute of Paris)

    badran.png Badran Raddaoui is an associate professor of computer science at the Polytechnic Institute of Paris. His research interests include reasoning under inconsistency and uncertainty, formal models of argumentation, satisfiability and constraints programming. Further topics that he is interested in concerns the application of symbolic AI techniques for data and graph mining.

  • Leander Hirschsteiner (to be PhD student)

    leander.jpg Leander is investigates what makes a good explanation. For him, explaining happens in argumentation

and dialogue and good explanations cater for the specific gaps in understanding of one’s partner. In his research, he develops models of these pratices so that humans and machines explain and understand one another (and themselves) more easily. Christian’s and Kees van Berkel’s supervision, as well as his background in the application of logical methods for formal modeling, defeasible reasoning, and social sciences, help him in this work.

Planned visits

  • Ofer Arieli will visit our group for 2 week in July 2025.
  • Badran Raddaoui will visit our group for 2 weeks in July 2025.