1 PREDICTING FRIENDSHIP INTENSITY IN ONLINE SOCIAL NETWORKS Waqar Ahmad, Asim Riaz, Henric Johnson, Niklas Lavesson Blekinge Institute of Technology School of Computing Karlskrona, Sweden. Abstract. Online social networks such as Facebook, Twitter, and MySpace have become preferred interaction, entertainment and socializing facility on the Internet. However, these social network services also bring privacy issues in more limelight than ever. Several privacy leakage issues are highlighted in the literature with a variety of suggested countermeasures. Most of these measures further add complexity and management overhead for the user. One ignored aspect with the architecture of online social networks is that they do not offer any mechanism to calculate the relationship strength between individuals. This information is quite useful to identify possible privacy threats. This study explores data mining techniques to predict the levels/intensity of friendship in online social networks. An online survey is conducted to analyze Facebook users’ interaction behavior with their good friends. This research also discovered mutual friends and profile visits; the two non-interaction based estimation metrics for friendship intensity. Finally, this study presents a data mining framework for predicting the strength of a relationship. This study concludes that factors such as current status, interaction type etc. need to be considered with the interaction count method in order to improve its performance. Furthermore, data mining techniques provide a natural way to integrate various factors in order to estimate friendship intensity. Keywords: Online Social Network, Friendship Intensity, Data Mining 1. INTRODUCTION The Internet, from its birth keeps on the tradition of providing different communication and information sharing services. Online social networks (OSNs) represent a recent type of communication and socializing platform [1], which is welcomed by the Internet users. Unlike the traditional web which revolves around information, documents, and web items, the concept of OSNs revolve around individuals, their connections and common interest-based communities. These online communities share or refer (provide links to other web resources) the traditional Internet resources with each other. An OSN consists of a virtual social graph where users are nodes who are connected with each other through a relationship, which forms the edges of the social graph. According to Antonio et al. [2], OSNs services for an individual are: (1) to create a public or semi public profile where he or she shares personal information such as name, contact, interests etc. (2) to establish a social circle of friends for information sharing and communication (3) to view and traverse friends’ profiles and private information (4) to carry out real time and non-real time communication with friends in the form of comments, private messaging, chatting, picture tagging etc. and (5) to use a lot of third party applications that range from simple poking to gaming, advance communication, virtual gifts, event management and so on.