Defeasible Reasoning and Uncertainty Management Systems II

DRUMS II - 6156

Work Area: Uncertainty Management

Keywords uncertainty, defeasible reasoning, non-monotonic deduction, inconsistency in reasoning, dynamic reasoning, abduction, probability theory

Start Date: 1 October 92 / Duration: 36 months / Status: starting

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Abstract DRUMS investigates the symbolic and quantitative methods of representation and reasoning able to deal with knowledge that is uncertain and defeasible. Six topics will be studied: belief change, non-monotonic deduction, inconsistency in reasoning, abduction, algorithmic problems and dynamic reasoning with partial models. The work builds on the results of DRUMS I (3085).

Aims

DRUMS II is a continuation of the DRUMS I Basic Research Action (3085), in which defeasible reasoning, uncertainty and incompleteness were studied. The overall objective is to investigate symbolic and quantitative methods of representation and reasoning able to deal with knowledge that is uncertain and defeasible. Six topics have been selected that are of fundamental importance in the domain of defeasible and uncertain reasoning:

• Belief change Organisation of the body of existing results for modelling belief changes so as to assess what is common to these belief change schemes.
• Non-monotonic deduction Integration of four general frameworks for deduction, namely Gentzen systems, labelled deductive systems, the axiomatisations of the consequence relation, and category theory; in order to provide appropriate insights into the nature and mechanism of non-monotonic deduction.
• Inconsistency in reasoning Development of a logic-based model that accounts for inconsistency in reasoning.
• Abduction Clarification of the relationships and actual differences of numerical, logical and machine learning perspectives of abduction.
• Algorithmic problems Study of the algorithmic problems of uncertain reasoning, taking as general a viewpoint as possible.
• Dynamic reasoning with partial models Study of the dynamics of non-monotonic reasoning using information structures as a vehicle for representation.

Approach and Methods

The project is centred on topics, and not on methods as was the case in DRUMS I. Partners are distributed amongst the six topics, creating a context favourable for strong integration between numerical and symbolic approaches as well as between various schools of thought.

Progress and Results

The major achievement is the integration of both the symbolic and numerical approaches for handling uncertainty problems, bridging the gaps between two usually diametrically opposed approaches. Strong cross-fertilisation is showing up. These collaborations are leading to several joint reports-publications. Many results will be presented at the European Conference ECSQARU-93 organised by DRUMS2. A series of handbooks is in preparation that will present DRUMS2 results. The use of these combined techniques for industrial problems are considered.

Potential

The project will provide a better understanding of the models proposed to represent and to handle uncertainty and defeasible reasoning, two topics that seem to have become major issues in the development of information systems.

Latest Publications

• Kohlas J, Monney P A Probabilistic Assumption Based Reasoning Uncertainty in A1-93, Morgan Kaufman, San Mateo, pp. 485-491 (1993)
• Dubois D, Prade H Graded Indiscernibility, fuzzy rough sets and modal logics, Proc. 5th ifsa World Congress, 85-88 (1993)
• Geerts P, Vormeir D A non-monotonic reasoning formalism using implicit specificity information, Proceedings of the second International Workshop on Logic and Non-monotonic Reasoning, 380-396, the MIT Press (1993)
• Smets P An axiomatic justification for the use of belief function to quantify beliefs IJCAI'93 (Inter. Joint Conf. on A1), Chambery, pp. 598-603 (1993)
• Clarke M, Kruse R, Moral S (Eds.) Symbolic and Quantitative Approaches to Reasoning and Uncertainty Lecture Notes in Computer Science 747, Springer Verlag (1993)

Information Dissemination Activies

DRUMS2 organised the 2nd European Conference on Symbolic and Quantitative Approaches to Reasoning and Uncertainty in Granada, Nov. 1993. Results of DRUMS2 projects will be published by Oxford University Press as a serie of 5 volumes called the "Handbook on Defeasible Reasoning and Uncertainty Management".

Coordinator

Université Libre de Bruxelles - B
Ave. Franklin Roosevelt 50
B - 1050 BRUXELLES

Partners

Universiteit Antwerpen - B
Universität Fribourg - CH
DFKI - D
Technische Universität Braunschweig - D
Aalborg Universitet - DK
Universidad de Granada - E
Centre D'Estudis Avancais de Blanes - E
CNRS-IRISA - F
Université Paul Sabatier - F
Université de Provence - F
CNRS-LRI - F
CNRS-IRIT - F
Università di Torino - I
Università di Catania - I
Universiteit van Amsterdam - NL
Lund Universitet - S
Linköping Universitet - S
Imperial College of Science, Technology and Medicine - UK
Queen Mary and Westfield College - UK

CONTACT POINT

Prof. P. Smets
tel +32/2 650 27 29
fax +32/2 650 27 15
e-mail: psmets@ulb.ac.be

DRUMS II - 6156, August 1994

please address enquiries to the ESPRIT Information Desk

html version of synopsis by Nick Cook