A variety of formalisms have been developed to address such
aspects of handling imperfect knowledge as uncertainty,
vagueness, imprecision, incompleteness, and partial
inconsistency. Some of the most familiar approaches in this
research field are nonmonotonic logics, modal logics,
probability theory (Bayesian and non-Bayesian), belief
function theory, and fuzzy sets and possibility theory.
ESPRIT Basic Research Action 3085, entitled Defeasible
Reasoning and Uncertainty Management Systems (DRUMS), aims
to contribute to the elucidation of similarities and
differences between these formalisms. It consists of 11
active European research groups. The European Conference on
Symbolic and Quantitative Approaches to Uncertainty (ESQAU)
provides a forum for these groups to meet and discuss their
scientific results.
This volume contains 42 contributions accepted for the ESQAU
meeting held in October 1991 in Marseille, together with 12
articles presenting the activities of the DRUMS groups and
two invited presentations.