Knowledge Representation and Reasoning

Welcome to the newly established group headed by Johannes (P.) Wallner, specializing on Knowledge Representation & Reasoning (KRR).

If you are interested in student topics (e.g., for a Bachelor's or Master's thesis) you can have look at the topics page. A Bachelor's or Master's thesis can be started anytime (contact).

Broadly construed, knowledge representation & reasoning in Artificial Intelligence is concerned with foundational research questions such as how to represent knowledge and how to reason based on knowledge. Our research and teaching focuses on

  • formal studies of prominent logic-based representations of knowledge, and
  • addressing challenging computational reasoning tasks arising in KRR.

Our research agenda is to further understanding of complex forms of reasoning in knowledge representation, and to bring promising approaches closer to application, by going from theory to practice.

One of our main current areas is computational argumentation. For a general introduction to the topic, you can have a look, e.g., at the Handbook of Formal Argumentation or this article

** News **: Call for applications to the Doctoral Consortium (DC) of KR'24.

** New course **: Logic-based Knowledge Representation (winter term).

Below you find recent news (news archive).

Recent News

Three papers accepted to COMMA 2024


Three of our works are accepted to COMMA 2024, a conference dedicated to computational argumentation. In the first work "Value-based Reasoning in ASPIC+" we investigate how value-based reasoning can be integrated in the argumentation formalism ASPIC+. In "On Computing Admissibility in ABA" we look at algorithmic approaches that compute compact representations of admissible sets of arguments in non-flat assumption-based argumentation. In the third work, "Complexity of Semi-Stable Semantics in Abstract Dialectical Frameworks", we extend the current state-of-the-art complexity analysis on abstract dialectical frameworks, by considering the recently introduced semi-stable semantics.  

Papers accepted to IJCAI 2024 and RATIO 2024


Our works on "Ranking Transition-based Medical Recommendations using Assumption-based Argumentation" and "Instantiations and Computational Aspects of Non-Flat Assumption-based Argumentation" have been accepted to RATIO and IJCAI 2024, respectively. RATIO is a new conference on advances in argumentation machines and IJCAI is a premier conference in Artificial Intelligence. 

In the first work we look at using a ranking-based semantics for assumption-based argumentation in a medical scenario. In the second work we look at issues arising when creating argument structures from a possibly conflicting knowledge base. We consider algorithmic approaches to address the issues. 

Invited Talk at SAFA


Co-located with 10th International Conference on Computational Models of Argument (COMMA 2024), Wallner will give an invited talk at the Fifth International Workshop on Systems and Algorithms for Formal Argumentation (SAFA 2024). This talk will give an overview of recent research in the area of algorithmic approaches to structured argumentation - focusing on the prominent approaches called assumption-based argumentation (ABA) and ASPIC+. 

Doctoral Consortium at KR 2024


We are co-organizing this year's edition of the Doctoral Consortium (DC) of the prominent International Conference on Principles of Knowledge Representation and Reasoning (KR'24). The DC is a student mentoring program bringing together PhD students and senior researchers from the area of KR. 

The call for applications is available at the KR'24 webpage

Extended abstract accepted to AAMAS'24


Our work on "Abstracting Assumptions in Structured Argumentation" will be presented at this year's edition of AAMAS, and an extended abstract of our work will be published in the proceedings of this conference. In this work we look at possibilities of simplifying - abstracting - argumentation scenarios in the prominent structured argumentation formalisms of assumption-based argumentation (ABA).

Workshop in Vienna


We are co-organizing a workshop with TU Wien on "Recent Advances in Collaborative and Argumentative Decision-Making". The workshop will take place at TU Wien on November 24th.

Research on supporting decision-making is central to classical and modern Artificial Intelligence. Decision-making with several parties plausibly often involves both collaborative aspects and consensus regarding diverging opinions and conflicts. Two major research strands in these directions are Social Choice Theory and Formal Argumentation. The former is concerned, e.g., with collective decision making such as voting, while the latter aims to provide rational conclusions under inconsistent information.

The aim of this workshop is to bring together researchers from several parts of the diverse fields of Computational Social Choice and Formal Argumentation, in order to discuss recent results and ongoing work on the new challenges.

The programme can be found at the website of the workshop.