Knowledge communities in grey

The dynamic nature of modern human social interactions, and the increasing capability of wireless and mobile devices for creating and sharing contents, open up the opportunity for a wide dissemination of information through complex knowledge sharing systems. As the shared knowledge components build cognitive ties, there is no real sharing of knowledge without a common understanding of it. In this article, particular emphasis is laid on technologies in Natural Language understanding and knowledge management for providing structured, intelligent access to the continuously evolving content, generated on-line in a pervasive collaborative environment. In detail, robust automated techniques for term extraction and knowledge acquisition are used to tap the information density and the global coherence of text excerpts sampled from both general-purpose and subject-specific social networks. We show empirically that the two sources may exhibit considerable differences in terms of content accessibility and informativeness.