With the growth-rate at which data is being collected and stored electronically in almost all fields of human endeavour, the efficient extraction of useful information from the data available is becoming an increasing scientific challenge and a massive economic need. This book presents reviewed and revised full versions of papers presented at a workshop on the topic held during KDD'99 in San Diego, California, USA in August 1999 complemented by several invited chapters and a detailed introductory survey in order to provide complete coverage of the relevant issues. The contributions presented...