Preface. Part I: Expositions. 1. Rough Sets; Z. Pawlak. 2. Data Mining: Trends in Research and Development; J. Deogun, et al. 3. A Review of Rough Set Models; Y.Y. Yao, et al. 4. Rough Control: A Perspective; T. Munakata. Part II: Applications. 5. Machine Learning & Knowledge Acquisition, Rough Sets, and the English Semantic Code; J. Grzymala-Busse, et al. 6. Generation of Multiple Knowledge from Databases Based on Rough Set Theory; X. Hu, et al. 7. Fuzzy Controllers: An Integrated Approach Based on Fuzzy Logic, Rough Sets, and Evolutionary Computing; T.Y. Lin. 8. Rough Real Functions and Rough Controllers; Z. Pawlak. 9. A Fusion of Rough Sets, Modified Rough Sets, and Genetic Algorithms for Hybrid Diagnostic Systems; R. Hashemi, et al. 10. Rough Sets as a Tool for Studying Attribute Dependencies in the Urinary Stones Treatment Data Set; J. Stefanowski, K. Slowinski. Part III: Related Areas. 11. Data Mining Using Attribute-Oriented Generalization and Information Reduction; N. Cercone, et al. 12. Neighborhoods, Rough Sets, and Query Relaxation in Cooperative Answering; J.B. Michael, T.Y. Lin. 13. Resolving Queries Through Cooperation in Multi-Agent Systems; Z. Ras. 14. Synthesis of Decision Systems From Data Tables; A. Skowron, L. Polkowski. 15. Combination of Rough and Fuzzy Sets Based on Alpha-Level Sets; Y.Y. Yao. 16. Theories that Combine Many Equivalence and Subset Relations; J. Zytkow, R. Zembowicz. Part IV: Generalization. 17. Generalized Rough Sets in Contextual Spaces; E. Bryniarski, U. Wybraniec- Skardowksa. 18. Maintenance of Reducts in the Variable Precision Rough Set Model; M. Kryszkiewicz. 19. Probabilistic Rough Classifiers with Mixture of Discrete and Continuous Attributes; A. Lenarcik, Z. Piasta. 20. Algebraic Formulation of Machine Learning Methods Based on Rough Sets, Matroid Theory, and Combinatorial Geometry; S. Tsumoto, H. Tanaka. 21. Topological Rough Algebras; A. Wasilewska. Index.