This volume contains articles accepted for presentation during The Intelli­ gent Information Systems Symposium IIS'2001 which was held in Zakopane, Poland, on June 18-22, 200l. This is tenth, in the order, symposium orga­ nized by the Institute of Computer Science of Polish Academy of Sciences and devoted to new trends in (broadly understood) Artificial Intelligence. The idea of organizing such meetings dates back to 1992. Our main in­ tention guided the first, rather small-audience, workshop in the series was to resume the results gained in Polish scientific centers as well as contrast them with the esea r rch performed by Polish scientists working at the uni­ versities in Europe and USA. This idea proved to be attractive enough that we decided to continue such meetings. As the years went by, the workshops has transformed into regular symposia devoted to 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 papers prepared by researches from Poland and other countries are usually presented. Besides, for several years now, the symposia are accompanied by a number of tutorials, given by the outstanding scientists in their domain.

Rule and Decision Tree Learning.- Identification of Rules for Brain Metastases and Survival Time Prediction for Small Cell Lung Cancer Patients.- The Development of the AQ20 Learning System and Initial Experiments.- Discovering Multi-head Attributional Rules in Large Databases.- Melanoma Prediction Using k-Nearest Neighbor and LEM2 Algorithms.- Technologies for Sound Database Indexing: Musical Instrument Classification Methods.- Unsupervised Learning.- Significance Testing in the Grade Correspondence Analysis.- Ensembles of Similarity-based Models.- Regression - Yet Another Clustering Method.- Taxonomy Building: Cases or Attributes ?.- Using Grade Correspondence Analysis to Merge Populations and Detect Latent Orders.- Mining the Preference Relations and Preference Graphs.- Biologically Motivated Methods.- Multi-Dimensional Gaussian and Cauchy Mutations.- Statistical Genetic Algorithms.- Cellular Automata Approach to Scheduling Problem in Case of Modifications of a Program Graph.- Multimodal Optimization with Artificial Immune Systems.- Learning and Reasoning Under Uncertainty.- Bayesian Network Mining System.- Intelligent Techniques in Stock Analysis.- Models of Multiple Response Independence.- The Role of Support and Confidence in Collaborative Query Answering.- Logical Foundations of Ai.- Criteria and Functions for Expert Information Representation Choice.- Intelligent Computing Systems with Actors - Parallel Dynamic Programming Algorithm of the Polygon Triangulation Problem.- A Model for Extracting a Class of Knowledge Operators, Logic Disjunctions and Logic Alternatives from BDI Agents.- Information Dimension of a Population's Attractor and Population's Entropy.- Quantifier Handling Issues in Computer-Oriented Intuitionistic Calculi.- Verification of theLogic of Plausible Reasoning.- Author Index.