For professionals and researchers in information and knowledge related technologies, Brena (distributed knowledge and multiagent systems, Tecnologico de Monterrey, Mexico) and Guzmán-Arenas (computer science, Centro de Investigación en Computación, Instituto Politécnico Nacional, Mexico) compile 11 articles that consider how to model the semantics of online documents and how to extract useful knowledge from them. Computer science and engineering researchers from South America, Europe, and Asia discuss a software system for topic discovery and document tagging, text representation models, query based topic modeling, a semantic relatedness measure, web search results discovery using multi-granular graphs, methods for learning argument preferences, a semantic evaluation framework to evaluate search systems, an approach to discovering and describing thematically related topics by graph clustering, and other topics. Annotation ©2012 Book News, Inc., Portland, OR (booknews.com)