This volume contains the papers selected for presentation at the 15th International S- posiumonMethodologiesforIntelligentSystems,ISMIS2005,heldinSaratogaSprings, NewYork,25-28May,2005. ThesymposiumwasorganizedbySUNYatAlbany. Itwas sponsored by the Army Research Of?ce and by several units of the University at Albany including its Division for Research, College of Arts and Sciences, Department of C- puter Science, and Institute for Informatics, Logics, and Security Studies (formerly the Institute for Programming and Logics). ISMIS is a conference series that was started in 1986 in Knoxville, Tennessee. Since then it has been held in Charlotte (North Carolina), Knoxville(Tennessee),Turin(Italy),Trondheim(Norway),Warsaw(Poland),Zakopane (Poland), Lyon (France), and Maebashi City (Japan). The Program Committee selected the following major areas for ISMIS 2005: intelligent information systems, knowledge discovery and data mining, knowledge - formation and integration, knowledge representation, logic for arti?cial intelligence, soft computing, Web intelligence, Web services, and papers dealing with applications of intelligent systems in complex/novel domains.The contributed papers were selected from almost 200 full draft papers by the Program Committee members: Troels Andreasen, Peter Baumgartner, Boualemn Benatallah, Salima Benbernou, Veronique Benzaken, Petr Berka, Elisa Bertino, Alan Biermann, Jacques Calmet, Sandra Carberry, Juan Carlos Cubero, Luigia Carlucci Aiello, Shu-Ching Chen, Christine Collet, Agnieszka Dardzinska, Ian Davidson, Robert Demolombe, Jitender Deogun, Jon Doyle, Tapio Elomaa, Attilio Giordana, Jerzy Grzymala-Busse,MirsadHadzikadic,ReinerHaehnle,JanuszKacprzyk,VipulKashyap, Jan Komorowski, Jacek Koronacki, Tsau Young Lin, Donato Malerba, David Maluf, Davide Martinenghi, Stan Matwin, Natasha Noy, Werner Nutt, James Peters, Jean-Marc Petit, Vijay Raghavan, Jan Rauch, Gilbert Ritschard, Erik Rosenthal, Marie-Christine Rousset, Nahid Shahmehri, Andrzej Skowron, Dominik Slezak, Nicolas Spyratos, V. S.
