Online social systems are multiplex in nature as multiple links may exist between the same two users across different social networks. In this work, we introduce a framework for studying links and interactions between users beyond the individual social network. Exploring the cross-section of two popular online platforms - Twitter and location-based social network Foursquare - we represent the two together as a composite multilayer online social network. Through this paradigm we study the interactions of pairs of users differentiating between those with links on one or both networks. We find that users with multiplex links, who are connected on both networks, interact more and have greater neighbourhood overlap on both platforms, in comparison with pairs who are connected on just one of the social networks. In particular, the most frequented locations of users are considerably closer, and similarity is considerably greater among multiplex links. We present a number of structural and interaction features, such as the multilayer Adamic Adar coefficient, which are based on the extension of the concept of the node neighbourhood beyond the single network. Our evaluation, which aims to shed light on the implications of multiplexity for the link generation process, shows that multilayer features, constructed from properties across social networks, perform better than their single network counterparts in predicting links across networks. We propose that combining information from multiple networks in a multilayer configuration can provide new insights into user interactions on online social networks, and can significantly improve link prediction overall with valuable applications to social bootstrapping and friend recommendations.
We use a social network approach to examine how work and friendship ties in a university research group were associated with the kinds of media used for different kinds of information exchange. The use of electronic mail, unscheduled face-to-face encounters, and scheduled face-to-face meetings predominated for the exchange of six kinds of information: Receiving Work, Giving Work, Collaborative Writing, Computer Programming, Sociability, and Major Emotional Support. Few pairs used synchronous desktop videoconferencing or the telephone. E-mail was used in similar ways as face-to-face communication. The more frequent the contact, the more “multiplex” the tie: A larger number of media was used to exchange a greater variety of information. The closeness of work ties and of friendship ties were each independently associated with more interaction: A greater frequency of communication, the exchange of more kinds of information, and the use of more media. © 1998 John Wiley & Sons, Inc. Social media treats all users the same: trusted friend or total stranger, with little or nothing in between. In reality, relationships fall everywhere along this spectrum, a topic social science has investigated for decades under the theme of tie strength. Our work bridges this gap between theory and practice. In this paper, we present a predictive model that maps social media data to tie strength. The model builds on a dataset of over 2,000 social media ties and performs quite well, distinguishing between strong and weak ties with over 85 accuracy. We complement these quantitative findings with interviews that unpack the relationships we could not predict. The paper concludes by illustrating how modeling tie strength can improve social media design elements, including privacy controls, message routing, friend introductions and information prioritization. This paper explores the impact of communication media and the Internet on connectivity between people. Results from a series of social network studies of media use are used as background for exploration of these impacts. These studies explored the use of all available media among members of an academic research group and among distance learners. Asking about media use as well as about the strength of the tie between communicating pairs revealed that those more strongly tied used more media to communicate than weak ties, and that media use within groups conformed to a unidimensional scale, showing a configuration of different tiers of media use supporting social networks of different ties strengths. These results lead to a number of implications regarding media and Internet connectivity, including: how media use can be added to characteristics of social network ties; how introducing a medium can create latent tie connectivity among group members that provides the technical means for activating weak ties, a... Social media allow for an unprecedented amount of interaction between people online. A fundamental aspect of human social behavior, however, is the tendency of people to associate themselves with like-minded individuals, forming homogeneous social circles both online and offline. In this work, we apply a new model that allows us to distinguish between social ties of varying strength, and to observe evidence of homophily with regards to politics, music, health, residential sector & year in college, within the online and offline social network of 74 college students. We present a multiplex network approach to social tie strength, here applied to mobile communication data - calls, text messages, and co-location, allowing us to dimensionally identify relationships by considering the number of communication channels utilized between students. We find that strong social ties are characterized by maximal use of communication channels, while weak ties by minimal use. We are able to identify 75 of close friendships, 90 of weaker ties, and 90 of Facebook friendships as compared to reported ground truth. We then show that stronger ties exhibit greater profile similarity than weaker ones. Apart from high homogeneity in social circles with respect to political and health aspects, we observe strong homophily driven by music, residential sector and year in college. Despite Facebook friendship being highly dependent on residence and year, exposure to less homogeneous content can be found in the online rather than the offline social circles of students, most notably in political and music aspects.