The program will include courses, keynotes, and the student program. Courses will introduce argumentation along different perspectives (abstract and structured level, argumentation as inference and argumentation as dialogues, probabilistic argumentation), and will deal with the application of argumentation for normative and legal reasoning, argument mining from natural language, and the use of a general software tool for argumentation. Keynotes will give a focused overview on a specific topic. The student program will consist of poster sessions and discussions with mentors (see Student Session). There are also several social events scheduled for the duration of SSA 2020. The preliminary overview of the programme is given below.

Friday 4/9/2020 Saturday 5/9/2020 Sunday 6/9/2020 Monday 7/9/2020 Tuesday 8/9/2020
09:15-09:30 Welcome
09:30-11:00 Abstract Arg (Baroni) Dialogues (Maudet, Parsons) Dialogues (Maudet, Parsons) KEYNOTE?
11:00-11:20 Coffee break Coffee break Coffee break Coffee break Coffee break
11:20-12:50 Abstract Arg (Baroni) Arg Mining (Torroni) Arg Mining (Torroni) Tweety (Thimm) STUDENT SESSION
12:50-14:10 Lunch break Lunch break Lunch break Lunch break Lunch break
14:10-15:40 Structured Arg (Modgil) Defeasible Logic (Governatori) Normative-Legal (Governatori, Sartor) Tweety (Thimm) STUDENT SESSION
15:40-16:00 Coffee break Coffee break Coffee break Coffee break Coffee break
16:00-17:30 Structured Arg (Modgil) Prob. Arg. (Flesca) Normative-Legal (Governatori, Sartor) KEYNOTE (Reed) STUDENT SESSION


Course: An introduction to abstract argumentation

Tutor: Pietro Baroni

Abstract: The course will provide an introduction to the theory of abstract argumentation frameworks, discussing its basic concepts and analyzing in detail the notion of abstract argumentation semantics, with a coverage of the general properties characterizing different semantics and of the main proposals available in the literature. After covering these foundational aspects, the final part of the course will give an overview of various research trends devoted to developing and extending the basic abstract argumentation model.

Course: Dialectical Formalisations of Non-monotonic Reasoning via Structured Argumentation

Tutor: Sanjay Modgil

Abstract: The aim of the tutorial is to give an overview of the ASPIC+ framework for structured argumentation, and developments and applications of ASPIC+. I will describe how the framework allows one to specify construction of arguments from a knowledge base (KB) of premises in a logical language of one's choosing, and inference rules of one's choosing, which may be the inference rules of a deductive logic and/or defeasible (default) inference rules. The constructed arguments can then be related to each other, according to whether one argument is a counter-argument to (i.e., 'attacks') another. Preferences over arguments can then determine which attacks are successful. The arguments, related by successful attacks, are then evaluated using Dung's argumentation theory (reviewed in the preceding tutorial by Pietro Baroni), so that the claims of the winning (justified) arguments identify the non-monotonic inferences from the underlying KB. ASPIC+ thus enables dialectical formalisations of non-monotonic logics, and so paves the way for distributed non-monotonic reasoning amongst multiple agents, in the form of dialogues (I will point to the importance of such dialogues in addressing ethical concerns relating to AI). Moreover, I will review ASPIC+ guidelines constraining the above choices, as well as how preferences are defined, in order to ensure that the outcome of argument evaluation yields rational outcomes. The tutorial will also cover some key developments of the ASPIC+ framework; notably: 1) A modification of ASPIC+ that studies preservation of rationality under resource bounds; 2) an extension of ASPIC+ that enables argumentation based reasoning about possibly conflicting preferences/values that are used to decide the success of attacks; 3) Evaluation of ASPIC+ arguments under generalisations of Dung's theory that yield more fine grained evaluation of the status of arguments (i.e., not just as winning, losing or undecided.

Course: Argumentation Mining

Tutor: Paolo Torroni

Abstract: TBA

Course: Defeasible Logic

Tutor: Guido Governatori

Abstract: Defeasible logic is a rule based proof theoretic computationally oriented non-monotonic logic whose reasoning mechanism is closely related to argumentation. In addition, the logic proved to be flexible enough to capture different and somehow incompatible facets of non-monotonic reasoning. In the lecture, we are going to present the basics of the logic, and how to generate variants modelling different aspects of non-monotonic reasoning. Moreover, we show how to provide argumentation semantics for the variants of the logic.

Course: Probabilistic Abstract Argumentation

Tutor: Sergio Flesca

Abstract: Several proposals have been made to model uncertainty in Abstract Argumentation Frameworks (AAFs), by considering weights, preferences, or probabilities associated with arguments and/or defeats. One of the most popular approaches based on probability theory for modeling the uncertainty is the so called constellations approach: the dispute is represented by means of a Probabilistic Argumentation Framework (prAAF), that consists in a set of alternative scenarios, each of which is represented by a (deterministic) AAF (or, equivalently, an argumentation graph) associated with a probability. The various works in the literature investigating prAAFs make different assumptions on how the probability distribution function (pdf) over the scenarios is specified, for instance assuming that the pdf is defined "extensively", by enumerating all the possible scenarios and, for each of them, the value of its probability, or adopting the restriction that arguments and defeats are independent and specifying only the marginal probabilities associated with arguments and defeats. In this talk we give an overview of Probabilistic Argumentation Frameworks and the reasoning problems defined over them and briefly describe the various research trends related to prAAFs.

Course: Argument-based Normative and Legal Reasoning

Tutor: Guido Governatori, Giovanni Sartor

Abstract: The course is organized into two lectures.
Defeasible Logic for Deontic Reasoning.
Normative reasoning incorporates two characteristic features: norms are defeasible (in the sense that typically they admit exceptions) and norms provide conditions under which obligations/permissions/prohibitions are in force in a normative system. Also, norms can be violated, and normative systems provide mechanisms to compensate for violations. In the lecture, we are going to show how to integrate in a computationally oriented way Defeasible Logic (for the efficient treatment of exceptions) and Deontic Logic of Violations. Examples from real-life norms illustrate how the resulting logic works.
Abstract for the second lecture TBA.

Course: Formal Argumentation Approaches in TweetyProject

Tutor: Matthias Thimm

Abstract: The TweetyProject ( is a collection of various Java libraries that implement approaches to different areas of artificial intelligence. In this tutorial, I provide an overview on the argumentation libraries of the TweetyProject. These libraries comprise of implementations to abstract argumentation frameworks, as well as the most popular approaches to structured argumentation (ASPIC+, ABA, Deductive Argumentation, DeLP), and various further aspects such as ranking and probabilistic semantics. I briefly sketch the functionalities of these libraries and give some pointers to how they can be used.

Invited Talk: TBA

Speaker: Chris Reed

Abstract: TBA.


Pietro Baroni - University of Brescia, Italy

Pietro Baroni is full professor of computer science and engineering at the Department of Information Engineering of the University of Brescia, Italy. He is author of more than 130 scientific papers in the area of artificial intelligence and knowledge-based systems, with a main focus on theory and applications of computational argumentation. He was a founding member of the Steering Committee of the COMMA (Computational Models of Argument) conference series, served as program chair of COMMA 2016, and is currently coEditor-in-Chief of the Argument & Computation journal.

Sergio Flesca - University of Calabria, Italy

Sergio Flesca is full professor at University of Calabria. He received a Ph.D. degree in Computer Science from University of Calabria. His research interests include databases, web and semi-structured data management, information extraction, inconsistent data management, approximate query answering, log analysis and mining, probabilistic argumentation frameworks and more recently uncertainty in argumentation.

Guido Governatori - Data61, CSIRO, Australia - Research Professor, Law School, La Trobe University, Melbourne, Australia

Guido Governatori is a Senior Principal Researcher at CSIRO’s Data61 where he leads the Software Systems Research Groups and also provides scientific leadership to the RegTech Technology Program. Before receiving his PhD in Legal Informatics from the University of Bologna, he graduated in Philosophy from the same university. Before joining NICTA (now CSIRO’s Data61) he held academic positions at Griffith University, Queensland University of Technology and the University of Queensland. His research focuses on non-monotonic and non-classical logics (specifically rule based logics) and their applications, in particular the field of legal reasoning and legal informatics, agents and business processes. His work on the application of Defeasible Deontic Logic for business processes started the investigation in the novel area of business process compliance and in 2018 the work was awarded the BPM Test of Time for the influence and impact the work created. In 2015 Guido received the Australian Computer Society ICT Researcher of the Year Gold Award. He served as program chair of the major international conference on modal and deontic logic, artificial intelligence and law, legal informatics and rules and reasoning.

John F. Horty

Nicolas Maudet

Sanjay Modgil - King's College London, UK

Sanjay Modgil is a reader in Artificial Intelligence and head of the Reasoning and Planning Group at King's College London. His main research and teaching interests are in the areas of logic, argumentation and dialogue, and philosophical and ethical issues related to AI. He has published over 90 published papers, with key research contributions in developing the ASPIC+ model of logic-based argumentation, dialectical models of logic-based reasoning that are provably rational under resource bounds, and models of logic-based argumentation that accommodate reasoning about preferences and values. More recently, he has focused on the ethics of AI, and integration of human and artificial agent reasoning through dialogues purposed to reason about moral issues.

Simon Parsons

Chris Reed - University of Dundee, Scotland

Chris Reed is Professor of Computer Science and Philosophy at the University of Dundee in Scotland, where he heads the Centre for Argument Technology. Chris has been working at the overlap between argumentation theory and artificial intelligence for over twenty years, has won £6m in funding and has over 200 publications in the area. He collaborates with a wide range of partners such as IBM and the BBC, and is also active in public engagement and commercialization of research, having served as executive director (CTO, CSO and CEO) of three start-up companies, and appearing in TV, radio and print media with a combined audience in excess of 29 million people.

Giovanni Sartor - University of Bologna, Italy

Matthias Thimm - Institute for Web Science and Technologies (WeST), Koblenz, Germany

Matthias Thimm is a senior researcher at the Institute for Web Science and Technologies (WeST) in Koblenz, Germany. His research focus is on formal methods of knowledge representation and artificial intelligence, both from a conceptual as well as algorithmic perspective. He is interested in formal models of argumentation, in particular with respect to quantitative extensions, algorithms and implementations, game-theoretical aspects for application in multi-agent systems, and the relationship of argumentation and belief revision. Further interests include inconsistency measurement, probabilistic reasoning with incomplete and inconsistent information in propositional and first-order representations of knowledge. He is co-founder of the International Competition of Computational Models of Argumentation (ICCMA) and member of the COMMA steering committee and the Argument and Computation Editorial Board.

Paolo Torroni - University of Bologna, Italy

Paolo Torroni is an associate professor with the University of Bologna since 2015. His main research focus is in artificial intelligence, and in particular argumentation mining, multi-agent systems, and computational logics, where he contributed within several national and international research projects. Since 2012 he teaches real time systems for automation in the automation engineering international master's degree. In 2018 he was awarded the national scientific qualification as full professor in "information processing systems" and "informatics".