WEBSOM - Self-organizing maps of document collections

With the WEBSOM method a textual document collection may be organized onto a graphical map display that provides an overview of the collection and fac ilitates interactive browsing. Interesting documents can be located on the map using a content-directed search. Each document is encoded as a histogra m of word categories which are formed by the self-organizing map (SOM) algo rithm based on the similarities in the contexts of the words. The encoded d ocuments an organized on another self-organizing map, a document map, on wh ich nearby locations contain similar documents. Special consideration is gi ven to the computation of very large document maps which is possible with g eneral-purpose computers if the dimensionality of the word category histogr ams is first reduced with a random mapping method and if computationally ef ficient algorithms are used in computing the SOMs. (C) 1998 Elsevier Scienc e B.V. All rights reserved.