This volume contains articles accepted for presentation during The Intelligent Information Systems Symposium IIS'2002 which was held in Sopot, Poland, on June 3-6, 2002. This is eleventh, in the order, symposium organized by the Institute of Computer Science of Polish Academy of Sciences and devoted to new trends in (broadly understood) ArtificialIntelligence. The meetings started back to 1992. With small initial audience, workshops in the series grew to an important meeting of Polish and foreign scientists working at the universities in Europe, Asia and the Northern America. Over years, the workshops transformed into regular symposia devoted to latest trends in such fields like Machine Learning, Knowledge Discovery, Natural Language Processing, Knowledge Based Systems and Reasoning, and Soft Computing (i.e. Fuzzy and Rough Sets, Bayesian Networks, Neural Networks and Evolutionary Algorithms). At present, about 50-60 papers are accepted each year. Besides, for several years now, the symposia are accompanied by a number of tutorials, given by the outstanding scientists in their domain. The main topics of this year symposium included: ¿ decision trees and other classifier systems ¿ neural network and biologiccally motivated systems ¿ clustering methods ¿ handling imprecision and uncertainty ¿ deductive, distributed and agent-based systems We were pleased to see the continuation of the last year trend towards an increase in the number of co-operative contributions and in the number and diversity of practical applications of theoretical research.

Decision Trees and Other Classifier Systems.- Neural Network and Biologically Motivated Systems.- Clustering Methods.- Handling Imprecision and Uncertainty.- Deductive, Distributed and Agent-based Systems.