Spectral Clustering in Social Networks -- Looking for Great Ideas: Analyzing the Innovation Jam -- Segmentation and Automated Social Hierarchy Detection through Email Network Analysis -- Mining Research Communities in Bibliographical Data -- Dynamics of a Collaborative Rating System -- Applying Link-Based Classification to Label Blogs -- Why We Twitter: An Analysis of a Microblogging Community -- A Recommender System Based on Local Random Walks and Spectral Methods.

This book constitutes the thoroughly refereed post-workshop proceedings of the 9th International Workshop on Mining Web Data, WEBKDD 2007, and the 1st International Workshop on Social Network Analysis, SNA-KDD 2007, jointly held in St. Jose, CA, USA in August 2007 in conjunction with the 13th ACM SIGKDD International Conference on Knowledge Discovery and Data Mining, KDD 2007. The 8 revised full papers presented together with a detailed preface went through two rounds of reviewing and improvement and were carefully selected from 23 initial submisssions. The enhanced papers address all current issues in Web mining and social network analysis, including traditional Web and semantic Web applications, the emerging applications of the Web as a social medium, as well as social network modeling and analysis.