Incomplete Data Decomposition for Classification Rafal Latkowski Institute of Computer Science, Warsaw University ul. Banacha 2, 02-097 Warsaw, Poland rlatkows@mimuw.edu.pl Abstract In this paper we present a method of data decomposition to avoid the necessity of reasoning on data with missing attribute values. The original incomplete data is decomposed into data subsets without missing values. Next, methods for classifier induction are applied to such sets. Finally, a conflict resolving method is used to combine partial answers from classifiers to obtain final classification. We provide an empirical evaluation of the decomposition method with use of various decomposition criteria.