• Banner

COMMA 2026

11th International Conference on Computational Models of Argument

Program

Schedule

TBA

Invited Talks

Ulrike Hahn

Birkbeck College, University of London, UK

Bayesian Argumentation from Single Arguments to Large-Scale Debate

Abstract

Over the past decades, the framework of Bayesian probability has successfully been applied to the task of evaluating argument quality: that is, the nuanced evaluation of content-based differences in argument strength for individual arguments, at least in the domain of facts. The Bayesian framework also deals naturally with the problem of aggregation that has bedevilled both argumentation theory and the design of practical argumentation systems. That is, it can provide overall, summary evaluation across multiple arguments in such a way as to yield a final conclusion strength. In this, it is complementary to other formal and computational approaches to argument that have focussed on the dialectical process of argument. The talk describes how core dialectical notions (such as defeat) are captured in a Bayesian framework. It then introduces ways in which it opens up research questions and facilitates progress in understanding what is simultaneously both one of the most important real-world forms of argument and one of the most neglected by argumentation theorists: polylogues involving argument across large groups such as online social networks.

Bio

Ulrike Hahn

Ulrike Hahn is a professor at the Department of Psychological Sciences at Birkbeck College, University of London, where she also serves as director of the Centre for Cognition, Computation and Modelling. Ulrike's main focus has been on questions of human rationality. Her research examines human judgment, decision-making, and the rationality of everyday argument. In recent years she has been particularly interested in how the larger communicative social networks that we are part of shape the accuracy of our beliefs. Here she has used Bayesian agent-based models to understand argument exchange within larger collectives. Ulrike has been a member of the Senior Editorial Board of Topics in Cognitive Science, an Action Editor for Psychonomic Bulletin & Review, for Cognitive Psychology, and, currently, is an AE for Psychological Science and a consulting editor for Psychological Review. She was awarded the Cognitive Section Prize by the British Psychological Society, the Kerstin Hesselgren Professorship by the Swedish Research Council, and the Anneliese Maier Research Award by the Alexander von Humboldt Foundation. She is a fellow of the German National Academy of Science (Leopoldina), a fellow of the Association for Psychological Science, a fellow of the Cognitive Science Society, and she received an honorary doctorate from Lund University, Sweden in 2017.

Guillem Alenyà

Institut de Robotica i Informàtica Industrial (IRI), CSIC and UPC, Barcelona

Solving conflicts in human-robot interaction: context, multiple-preferences, and learning

Abstract

Autonomous agents operating in unstructured human environments must perform continuous decision-making under high degrees of uncertainty. These processes are typically constrained by partially observable states, stochastic sensor noise, and aleatory model inaccuracies. To mitigate these challenges, formal argumentation systems provide a robust framework for disambiguation and verifiable explainability (XAI). Within the domain of assistive robotics, such systems enable agents to synthesize multi-user context and conflicting arguments into coherent action policies. Furthermore, we highlight the advantage that the agent can proactively initiate active information-gathering tasks to resolve knowledge gaps and refine its internal world model.

Bio

Guillem Alenyà

Guillem Alenyà is a Researcher and Director at the Institut de Robotica i Informàtica Industrial (IRI), a joint centre of the Spanish Scientific Research Council (CSIC) and Polytechnic University of Catalonia (UPC). In the last 5 years, he has contributed novel approaches to the areas of learning and HRI devoted to facilitating the introduction of robots in human environments, principally in the fields of assistive robotics and garment manipulation. He is currently promoting LabORA, a new Open Lab devoted to bringing Assistive Robotics closer to societal needs. This is a 500m² new facility with an initial investment of 2.5M€ accompanied by the creation of a promoting group initially composed of more than 10 other research groups, hospitals, day-care facilities, service and technology industries, and governmental agencies.

Accepted Submissions

The following papers and demonstration abstracts have been accepted to COMMA 2026. The full program schedule will be announced soon.

Full Papers

(43 submissions)
  1. Lost in Translation: Towards Explainable Instantiated Argumentation Frameworks Shawn Bowers and Bertram Ludäscher
  2. Identifying Implicit Premises for Logical Reconstruction of Argument Graphs Xuyao Feng and Anthony Hunter
  3. Argument Accrual, ASPIC+ and Bipolar Argumentation Frameworks Henry Prakken
  4. On the Complexity of Initial Models in Abstract Dialectical Frameworks Hannes Strass and Johannes Peter Wallner
  5. On Grounding Extensions in Abstract Argumentation Lars Bengel, Shawn Bowers, Bertram Ludäscher and Matthias Thimm
  6. Explaining Vacuity in Abstract Argumentation Theodoros Doukas and Matthias Thimm
  7. Can Large Language Models Identify Reasoning Patterns in Low-Resource Languages? A Case Study of Argumentation Schemes in Catalan Ramon Ruiz-Dolz and Stella Heras
  8. Guiding Admissibility Solvers via Co-Admissibility Predictions Sandra Hoffmann, Isabelle Kuhlmann and Matthias Thimm
  9. A Neural Approach for Incomplete Argumentation Frameworks Cassandre Azeau and Jean-Guy Mailly
  10. An Exploratory Inquiry into Arguing Under Extortion Pietro Baroni, Federico Cerutti, Brilant Gashi, Massimiliano Giacomin, Andrea Loreggia and Enrico Scala
  11. On Polymorphic Attacks in ASPIC+ Pietro Baroni, Federico Cerutti and Massimiliano Giacomin
  12. Streamlining Argumentative Explanation for A Fortiori Reasoning in Inconsistent Case Bases Wachara Fungwacharakorn, Gauvain Bourgne and Ken Satoh
  13. Do Justified Arguments Matter for Bayesian Portfolio Optimisation? Anthony Young
  14. External Semantics For Argumentation Frameworks Yi Yutong and Weiwei Chen
  15. Do Argumentation Schemes Help? An Assessment of Their Role in Formalising Natural Language Arguments Ameer Saadat-Yazdi, Victor David, Anthony Hunter and Serena Villata
  16. Toulmin Argumentation Logic Floris Bex and Henry Prakken
  17. LLM-Assisted Legal Propositions Identification from Party Arguments in the U.S. Supreme Court Briefs Heng Zheng and Alex Zhang
  18. Cost-Aware Strategic Enforcement: An Analysis of Counting Semantics Kenji Imai and Ryuta Arisaka
  19. Representation Guarantees for Multi-Agent Knowledge Integration via Abstract Argumentation and Their Computational Complexity Naoki Susami and Ryuta Arisaka
  20. Aggregating Ranking-based Semantics in Abstract Argumentation Ulla Wege, Kenneth Skiba and Matthias Thimm
  21. Benchmarking Argumentative Behaviour of LLMs: A Study of Defences Against Character Attacks Ewelina Gajewska, Katarzyna Budzynska and Jarosław A. Chudziak
  22. Satisfying Rationality Postulates of Structured Argumentation Through Deductive Support Tom Friese and Marcos Cramer
  23. Better than the Gold Standard? Evaluating Human vs. LLM Enthymeme Reconstruction in Natural Language Argumentation Ekaterina Sviridova, Elena Cabrio and Serena Villata
  24. A Framework and Agent Strategies for ASPIC+-Based Advisory Dialogues Michael Mueller
  25. Complexity of Preferred Semantics in Infinite Argumentation Uri Andrews and Luca San Mauro
  26. A Conversation-Based Approach to Doxastic and Deontic Inference Kees van Berkel, Isabella Cissell and Blaž Istenič Urh
  27. Forgetting in ASPIC+: formulas, premises, rules and conclusions Annemarie Borg
  28. ClinArgES: Clinical Argumentation Spanish Corpus Raquel Martínez
  29. Multimodal Stance Detection in Controversial Tweets Deborah Dore, Diego Blassio, Elena Cabrio and Serena Villata
  30. Denial Integrity Constraints in Assumption-Based Argumentation Giovanni Buraglio, Anna Rapberger and Stefan Woltran
  31. A Unified Framework for Argumentation Protocols Théophile Romieu, Elise Bonzon, Jérôme Delobelle and Julien Rossit
  32. On the Role of Premises in Assessing the Strength of Analogical Arguments Leila Amgoud, Marco Hanocq and Marie-Christine Lagasquie-Schiex
  33. Truth Logic and Inquiry: Arguments For The Dialectical Turn in Non-monotonic Reasoning Sanjay Modgil
  34. Assumption-based Argumentation Through the Lens of Approximation Fixpoint Theory Iosif Apostolakis, Hannes Strass and Johannes Peter Wallner
  35. Simplifying Structured Arguments in Hierarchical Case-Based Reasoning Ilaria Canavotto
  36. A dialectical argumentation system for collision avoidance between drones Evandro Pioli Moro, Elizabeth Black and Anthony Hunter
  37. Defeasible Case-Based Reasoning in Ethics: A Logic-Based Argumentative Model Luca Redondi
  38. Probabilistic Subargument Argumentation Frameworks Chenyang Cai, Beishui Liao and Chen Chen
  39. On the Relationship of Unacceptable Arguments to Acceptable Extensions John Spoerl
  40. Constructing Compact Structured Argumentation Frameworks Tuomo Lehtonen
  41. Beyond But-for Test: Counterfactual Explanation in Abstract Argumentation via Actual Causality Siyi Liu, Muyun Shao and Beishui Liao
  42. The Libra Dialogue Protocol for Comparative Deliberation Luca Pasetto, Thomas Skafte, Leendert van der Torre and Liuwen Yu
  43. How Can Similarity Be Explained? Modeling Multiple Points of View with Inverse simFOL Nino Pireaud, Victor David, Pierre Monnin, Elena Cabrio, Serena Villata and Anthony Hunter

Demonstration Abstracts

(8 submissions)
  1. The Jiminy moral advisor: a Python implementation Francisco J. Rodriguez Lera, Miguel Ángel González-Santamarta and Pere Pardo
  2. Argumentation-based Causal Reasoning Lars Bengel, Oleksandr Dzhychko, Myriam Kasten, Kai Sauerwald and Matthias Thimm
  3. ABDA-NL: A Natural-Language Scenario Explorer for Argument-Based Reasoning Shawn Bowers, Martin Caminada, Haoyang Liu and Bertram Ludäscher
  4. Tag Me Maybe: A Flexible Environment for Annotating Argumentation Daniel Ziembicki
  5. ArguScope: A Visual Argumentation Tool for Priority-Aware Reasoning Jack Mumford, Nataliya Gulay, Dmytro Antypov, Luke M. Daniels, Matthew S. Dyer, Sven Schewe, Katie Atkinson and Matthew J. Rosseinsky
  6. ADICT: Argumentative Dialogue Convergence Tracker Youcef Islam Ghodbane, Yann Gabay, Gowrishankar Ganesh and Madalina Croitoru
  7. Constructing Arguments Using The Simple Argument Description Notation Simon Wells and Mark Snaith
  8. ArgBlazer: Exploring Decision Landscapes Using Argumentation Frameworks Meng Li, Timothy McPhillips, Shawn Bowers and Bertram Ludäscher

Important Dates

  • Early registration deadline for COMMA and SSA:
  • Early registration deadline for workshops:
  • Summer School:
  • Workshops:
  • Conference: