Linking Social Networks on the Web with FOAF: A Semantic Web Case Study

One of the core goals of the Semantic Web is to store data in distributed locations, and use ontologies and reasoning to aggregate it. Social networking is a large movement on the web, and social networking data using the Friend of a Friend (FOAF) vocabulary makes up a significant portion of all data on the Semantic Web. Many traditional web-based social networks share their members’ information in FOAF format. While this is by far the largest source of FOAF online, there is no information about whether the social network models from each network overlap to create a larger unified social network, or whether they are simply isolated components. If there are intersections, it is evidence that Semantic Web representations and technologies are being used to create interesting, useful data models. In this paper, we present a study of the intersection of FOAF data found in many online social networks. Using the semantics of the FOAF ontology and applying Semantic Web reasoning techniques, we show that a significant percentage of profiles can be merged from multiple networks. We present results on how this affects network structure and what it says about the success of the Semantic Web.