Social Networks
A social network represents the relationships people and organizations have. Social network analysis studies these relationships and their applications.
Among the classic social network analysis are the small world problem, from Stanley Milgram, the small world phenomenon, from Duncan Watts and Steven Strogatz, and the strength of weak ties, from Granovetter. These studies demonstrate how connected we all are and how important social networks are for the dissemination of information.
Many researchers have studied the impact and the potential social networks have on applications such as e-mail (e.g. Malone et al. with the Information Lens System), mailing lists (e.g. Goldberg et al. with Collaborative Filtering), newsgroups (e.g. Riedl et al. with Grouplens), personal sites (e.g. Kautz et al. with the Hidden Web), search engines (e.g. Brin and Page with PageRank), recommender systems (e.g. Maes et al. with Social Information Filtering), reputation systems (e.g. Resnick et al. with Reputation Systems), peer-to-peer networks (e.g. Grassman et al. with Social Networks in Peer-to-Peer), instant messaging (e.g. Smith with I.M. as a Scale-Free Network) and blogs (e.g. Kumar et al. with Structure and Evolution of Blogspace).
Web applications that help people organize their social network online are very popular. Some examples are MySpace, Facebook, and Orkut. These applications are walled gardens, but open standards such as FOAF (Friend of a Friend) and XFN (XHTML Friends Network) also exist.
