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.
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.
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
Publications produced during the project
Software produced during the project