INCREMENTAL CONCEPTUAL CLUSTERING WITHOUT ORDER DEPENDENCY Altintas, Nesip Ilker M.S., Department of Computer Engineering Supervisor: Assist. Prof. Dr. Cem Bozsahin September 1995, 69 pages -------------------------------------------------------------------- In this thesis, a new system for incremental conceptual clustering is presented. Incremental conceptual clustering systems integrate the learning with performance and obey the basic principles of human concept learning. As in other incremental learning systems, they are faced with the problem of dependency on the order of instance presentation. This study primarily focuses on this problem. The presented model is capable of learning a hierarchy of concepts while minimizing the order bias introduced due to its incremental nature. The learning process is divided into two phases: nonincremental clustering part and incremental refinement part. It has an entropy-based similarity measure in construction and refinement of the concept hierarchy. It makes use of an attribute-based metric to obtain concept stability, and an instance-based metric for tree stability. The system has been implemented, and experiments have been performed in several domains to measure the applicability of the system. The results showed that the conceptual validity of the concept hierarchy is high, and the effect of order of instance arrivals is minimized. --------------------------------------------------------------------- Keywords: Inductive learning, Conceptual clustering, Incremental learning.