Semantics in social tagging systems: A review

Web 2.0 brought many collaborative and novel applications which transformed the web as medium and resulted in exponential growth of the web. Tagging systems are one of these killer applications. As tags represent the link between objective information and users´ cognitive information, they have ambiguity problem reducing precision. Hence search and retrieval pose a challenge on folksonomy systems having unstructured, non-hierarchical organization with unsupervised vocabulary. We present a brief survey of different approaches related to resolving ambiguity and bringing structure and semantics in the social tagging model.