Prior Conceptual Knowledge in Machine Learning and Knowledge Discovery.- On Ontologies as Prior Conceptual Knowledge in Inductive Logic Programming.- A Knowledge-Intensive Approach for Semi-automatic Causal Subgroup Discovery.- A Study of the SEMINTEC Approach to Frequent Pattern Mining.- Partitional Conceptual Clustering of Web Resources Annotated with Ontology Languages.- The Ex Project: Web Information Extraction Using Extraction Ontologies.- Dealing with Background Knowledge in the SEWEBAR Project.- Web Mining 2.0.- Item Weighting Techniques for Collaborative Filtering.- Using Term-Matching Algorithms for the Annotation of Geo-services.

This book is showcases recent advances in knowledge discovery enhanced with semantic and social information. It includes eight chapters that grew out of joint workshops at ECML/PKDD 2007. The contributions emphasize the vision of the Web as a social medium.