Automatic Labeling of Self-Organizing Maps: Making a Treasure--Map Reveal its Secrets Andreas Rauber and Dieter Merkl Institut f{\"u}r Softwaretechnik, Technische Universitaet Wien, Resselgasse 3/188, A--1040 Wien, Austria {andi, dieter}@ifs.tuwien.ac.at Abstract: Self-organizing maps are an unsupervised neural network model which lends itself to the cluster analysis of high-dimensional input data. However, interpreting a trained map proves to be difficult because the features responsible for a specific cluster assignment are not evident from the resulting map representation. In this paper we present our {\em LabelSOM} approach for automatically labeling a trained self-organizing map with the features of the input data that are the most relevant ones for the assignment of a set of input data to a particular cluster. The resulting labeled map allows the user to better understand the structure and the information available in the map and the reason for a specific map organization, especially when only little prior information on the data set and its characteristics is available. Keywords: Data Visualization, Neural Networks, Dimensionality Reduction, Text Data Mining, Cluster Analysis ----- A. Rauber and D. Merkl. Automatic Labeling of Self-Organizing Maps: Making a Treasure-Map Reveal its Secrets In Proceedings of the 3. Pacific-Asia Conference on Knowledge Discovery and Data Mining (PAKDD'99), Bejing, China, April 26--28, 1999. LNCS / Lecture Notes in Artificial Intelligence, LNAI 1574, pp. 228 - 237, Springer Verlag