Argumentation Factory


Argumentation Factory

Algorithms and Software for Industrial Strength Inconsistency Tolerance




An EPSRC Funded Project (funded from January 2007 to January 2010)


For more information on the project, please contact Anthony Hunter (University College London).


Summary

In this project, we have been developing the argumentation factory as a software system that acts as a middle layer (or hub) between: knowledge resources (such as available in relational databases, logical knowledgebases, ontologies, and argumentbases marked up in the Argument Interchange Format) and diverse applictations of agumentation systems (such as for decision support, for multi-agent negotiation, for knowledge fusion, and for software requirements engineering).

To realise this goal, we have extended and refined the theoretical foundations and algorithms for argumentation, and undertake theoretical and empirical evaluations of our proposals. The main problem we have had to address is the inherent computational complexity involved in constructing arguments and counterarguments. Our computational approach is to search for arguments and counterarguments using only the subset of the knowledgebase that can play a role in a proof for an argument or counterargument. For this, we have adapted an existing automated reasoning approach called connection graphs. We have developed the theory for showing that the approach is sound and complete for propositional logic (CNF) and for first-order logic (Prenex quantified clausal knowledge). We have implemented the algorithms, and we have undertaken empirical studies to show the viability of the approach. The propositional version is currently available by request, and the first order version will be available later this year.

In addition, we have been developing the theory and applications of the project in monological and dialogical argumentation including the formalization of weighted abstract argumentation systems, the analysis of the appropriateness of proponents of arguments, the handling of enthymemes (arguments without sufficient premises with which to infer the claim but which rely on common knowledge to allow the inference), the mechanisation of argument-based multi-agent decision-support, and the use of distributed conflicting ontologies.

Finally, during the project, we completed Elements of Argumentation which was co-authored by Philippe Besnard and Anthony Hunter, and published by MIT Press.


Publications produced during the project

  • V Efstathiou and A Hunter (2010) A Computational Framework for Generating Arguments in Clausal Logic, International Journal of Approximate Reasoning, (submitted).
  • P Dunne, A Hunter, P McBurney, S Parsons, M Wooldridge (2010) Weighted Argument Systems, Artificial Intelligence, (accepted subject to revision).
  • E Black and A Hunter (2010) A Relevance-theoretic Framework for Constructing and Deconstructing Enthymemes, Journal of Logic and Computation (in press).
  • M V Martinez and A Hunter (2009) Incorporating Classical Logic Argumentation into Policy-based Inconsistency Management in Relational Databases, in The Uses of Computational Argumentation Symposium, AAAI 2009 Fall Symposium Series.
  • E Black, A Hunter and J Pan (2009) An Argument-based Approach to Using Multiple Ontologies, Third International Conference on Scalable Uncertainty Management (SUM'09), LNCS 5785, Springer, pages 68-79.
  • Ph Besnard, A Hunter and S Woltran (2009) Encoding Deductive Argumentation in Quantified Boolean Formulae, Artificial Intelligence, 173:1406-1423.
  • Ph Besnard and A Hunter (2009) Argumentation based on Classical Logic, in Argumentation in Artificial Intelligence, edited by I Rahwan and G Simari, Springer.
  • E Black and A Hunter (2009) An Inquiry Dialogue System, Autonomous Agents and Multi-Agent Systems, 19(2):173-209.
  • P Dunne, A Hunter, P McBurney, S Parsons, M Wooldridge (2009) Inconsistency Tolerance in Weighted Argument Systems, Proceedings of the Eighth International Joint Conference on Autonomous Agents and Multi-Agent Systems (AAMAS'09), ACM Press, pages 851-858.
  • V Efstathiou and A Hunter (2009) An Algorithm for Generating Arguments in Classical Predicate Logic, Quantitative and Qualitative Approaches to Reasoning and Uncertainty (ECSQARU'09), LNCS, Springer, vol 5590, pages 119-130.
  • A Hunter (2008) Reasoning about the Appropriateness of Proponents for Arguments, Proceedings of the 23rd AAAI Conference on Artificial Intelligence (AAAI'08), pages 89-94, MIT Press.
  • E Black and A Hunter (2008) Using Enthymemes in an Inquiry Dialogue System, Proceedings of the Seventh International Joint Conference on Autonomous Agents and Multi-Agent Systems (AAMAS'08), pages 437-444, ACM Press.
  • V Efstathiou and A Hunter (2008) Algorithms for Effective Argumentation in Classical Propositional Logic, Proceedings of the International Symosium on Foundations of Information and Knowledge Systems (FOIKS'08), LNCS volume 4932, pages 272-290, Springer.
  • V Efstathiou and A Hunter (2008) Focused Search for Arguments from Propositional Knowledge, Proceedings of the Second International Conference on Computational Models of Argument (COMMA'08), pages 159-170, IOS Press.
  • N Mann and A Hunter (2008) Argumentation using Temporal Knowledge, Proceedings of the Second International Conference on Computational Models of Argument (COMMA'08), pages 204-215, IOS Press.
  • A Hunter (2007) Real Arguments are Approximate Arguments, Proceedings of the 22nd AAAI Conference on Artificial Intelligence (AAAI'07), pages 66-71, MIT Press.
  • E Black and A Hunter (2007) A Generative Inquiry Dialogue System, Proceedings of the Sixth International Joint Conference on Autonomous Agents and Multi-Agent Systems (AAMAS'07), ACM Press

  • Software produced during the project

    We have implemented our argument engine in Java which produces arguments and counterarguments from a knowledgebase of clauses. Each argument is a pair (X,p) where X is a minimal consistent set of clauses that entails the clause p, and each counterargument is an undercut to an argument or an undercut to a counterargument. Please contact Anthony Hunter (a.hunter@cs.ucl.ac.uk) for this software. A first-order version of this software will be available later this year.