Part I. Regular Sessions: Knowledge Discovery and Exploration -- Part II. Regular Sessions: Computational Linguistics -- Part III. Regular Sessions: Search Engines -- Part IV. Regular Sessions: Biologically Motivated Algorithms and Systems -- Part V. Regular Sessions: Statistical and Database Methods in AI -- Part VI. Poster Session -- Part VII. Invited Session: Syntactic Parsing and Machine Learning -- Part VIII. Invited Session: New Trends in Data Mining and Knowledge Discovery in Uncertain, Nonstationary Spatio-Temporal Data -- Part IX. Invited Session: Knowledge Base Systems -- Part X. Invited Session: KDD and Facial Recognition -- Part XI. Invited Session: Recent Developments in Bioinformatics -- Part XII. Special Session: Artificial Immune Systems.This edited book contains articles accepted for presentation during the conference "Intelligent Information Systems 2005 (IIS 2005) - New Trends in Intelligent Information Processing and Web Mining" held in Gdansk, Poland, on June 13-16, 2005. Special attention is devoted to the newest developments in the areas of Artificial Immune Systems, Search engines, Computational Linguistics and Knowledge Discovery. The focus of this book is also on new computing paradigms including biologically motivated methods, quantum computing, DNA computing, advanced data analysis, new machine learning paradigms, reasoning technologies, natural language processing and new optimization techniques.