TOPIC ISLANDS—a wavelet-based text visualization system

We present a novel approach to visualize and explore unstructured text. The underlying technology, called TOPIC-O-GRAPHYTM, applies wavelet transforms to a custom digi tal signal constructed from words within a document. The resultant multiresolution wavelet energy is used to analyze the characteristics of the narrative flow in the frequency domain, such as theme changes, which is then related to the overall thematic content of the text document using statistical methods. The thematic characteristics of a document can be analyzed at varying degrees of detail, ranging from section-sized text partitions to partitions consisting of a few words. Using this technology, we are developing a visualization system prototype known as TOPIC ISLANDSTM to browse a document, generate fuzzy document outlines, summarize text by levels of detail and according to user interests, define meaningful subdocuments, query text content, and provide sum- maries of topic evolution. Keywords: text visualization, information visualization, wavelet transform, and information retrieval.