Computer wavelet tool filters information

The amount of information available to businesses, governments and scientists today is unprecedented. To combat the growing problem of information overload, mathematicians and computer scientists at Pacific Northwest National Laboratory have developed TOPIC ISLANDSTM, an interactive software program that transforms data from large documents into visualizations and excerpted summaries. It recognizes themes and the evolution of topics within a document and then breaks it into easily understandable sections.

"This technology could help people who are overloaded with information, such as teachers, researchers and lawyers," said Rik Littlefield, senior research scientist at Pacific Northwest. "They could find out what topics are discussed in a document and to what degree, without having to spend 10 hours reading."

TOPIC ISLANDS creates visual outlines using Roman numerals to depict major themes and letters to indicate subtopics. The program categorizes the document into themes using algorithms and can process many pages simultaneously.

The underlying technology, called TOPIC-O-GRAPHYTM, works by creating a digital signal using words within a document. The signal is input to a wavelet engine - a tool that mathematically filters the signal to varying degrees. TOPIC ISLANDS can be tailored to a person's needs by further filtering the text to create more detailed information of theme changes. The resulting thematic structure can be visually presented in many different ways, or can be formatted into a table of contents with emphasis on the most prominent themes.

For more information, see Pacific Northwest's information visualization Web site at or contact Staci West at (509) 372-6313 or via e-mail at

This article originally appeared in the 05/01/1999 issue of Environmental Protection.

About the Author

Gerald F. Connell, ChE is a consultant, retired after 30 years with Capital Controls Group, Severn Trent Service Inc., Colmar, Pa. Mr. Connell is author of "The Chlorination/Chloramination Handbook," published by the American Water Works, and a forthcoming "Chlorination/Dechlorination Handbook" to be published by WEF.

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