Computer scientists and engineers, social scientists, and business scholars explain techniques for measuring the robustness of a social network, focusing on those that exist only on the Internet. After reviewing social networks and communities in general, they consider social networks and online communities from the perspectives of modeling and developing, information and knowledge discovery and diffusion, evolution, and business impact. Specific topics examined include from traditional society to the virtual sphere, analyzing success factors in social networking website development, information diffusion in social networks, observing the evolution of a learning community using social network analysis, and community structure extraction for social networks. Annotation ©2012 Book News, Inc., Portland, OR (booknews.com)