The 48 revised full papers and 15 revised short papers presented together with 4 invited/keynote papers and 2 tutorial papers were carefully reviewed and selected from 169 submissions. The papers are organized in topical sections on data mining and knowledge discovery, wireless, sensor networks and grid, XML and query processing and optimization, privacy and security, information extraction, presentation and retrieval, P2P, agent systems, ontology, semantic Web and Web applications, data streams, time series analysis and data mining, Web mining and Web search, as well as workflow and middleware.