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. Author Keywords Social media, social networks, relationship modeling, ties,

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this article, I will provide some history of SNA and its uses in library and information science. Although SNA resonates with the quantitative methodologies of bibliometricians, it has also been used in a qualitative manner to explore information seeking practices and information uses. While SNA may be a valuable tool, it is not a panacea. Recent sociological study illustrates the communication difficulties inherent in social systems. The results of these studies may provide important lessons for librarians. The article concludes with an example of how we may reconsider the bounds of codified information and social communication. In this case, I present an information retrieval system for email archives that exploits social networks in an attempt to both improve precision and address the unstated need of poorly formulated questions. Social Network Theory One of the stated goals of libraries is to provide information to patrons. In his recommendations for library service, for example, Ranganathan suggested: "Every reader his book." (1931) The world has moved on from the days of Dewey and Cutter but perhaps not as much as one would expect. Our interpretation of information for patrons is still largely "information as thing"---books, CDs, and journal articles (Buckland, 1991). The current ALA Code of Ethics mandates that "[w]e provide the highest level of service to all library users through appropriate and usefully organized resources." (Code of Ethics of the American Library Association, 1995) While we as librarians can readily describe means of accessing codified information such as books, journals, and web sites, we may struggle with the "other sources" that may not readily resemble printed codices but are vitally important information sources. One approa...

The production of scientific knowledge has evolved from a process of inquiry largely based on the activities of individual scientists to one grounded in the collaborative efforts of specialized research teams. This shift brings to light a new question: how the composition of scientific teams impacts their production of knowledge. This study employs data from 1,415 experiments conducted at the National High Magnetic Field Laboratory (NHMFL) between 2005 and 2008 to identify and select a sample of 89 teams, and examine whether team diversity and network characteristics impact productivity. The study examines how the diversity of science teams along several variables impacts overall team productivity. Results indicate several diversity measures associated with network position and team productivity. Teams with mixed institutional associations were more central to the overall network compared to teams composed primarily of the NHMFL’s own scientists. Team cohesion was positively related to productivity. The study indicates that high productivity in teams is associated with high disciplinary diversity and low seniority diversity of team membership. Finally, an increase in the share of senior members negatively affects productivity, and teams with members

Abstract: This paper discusses the role of network relationships in the internationalisation of small knowledge-intensive firms (SKIFs) by specifically highlighting their foreign, spatially scattered network relationships, which can be a significant international resource. Two issues are dealt with: how foreign network relationships are developed, and the impact they have on the internationalisation of SKIFs, specifically in relation to international market entry and development. This paper focuses on a developing economy context and cites the example of four small Indian software firms. Three effects of foreign network relationships on the internationalisation of SKIFs viz., opportunities, information and advice, are noted. 1.

bridging social capital, happiness, satisfaction with life, loneliness, depression, positive affect, negative affect,

Online communities in the form of message boards, listservs, and newsgroups continue to represent a considerable amount of the social activity on the Internet. Every year thousands of groups flourish while others decline into relative obscurity; likewise, millions of members join a new community every year, some of whom will come to manage or moderate the conversation while others simply sit by the sidelines and observe. These processes of group formation, growth, and dissolution are central in social science, and in an online venue they have ramifications for the design and development of community software. In this paper we explore a large corpus of thriving online communities. These groups vary widely in size, moderation and privacy, and cover an equally diverse set of subject matter. We present a broad range of descriptive statistics of these groups. Using metadata from groups, members, and individual messages, we identify users who post and are replied-to frequently by multiple group members; we classify these high-engagement users based on the longevity of their engagements. We show that users who will go on to become long-lived, highly-engaged users experience significantly better treatment than other users from the moment they join the group, well before there is an opportunity for them to develop a long-standing relationship with members of the group. We present a simple model explaining long-term heavy engagement as a combination of user-dependent and groupdependent factors. Using this model as an analytical tool, we show that properties of the user alone are sufficient to explain 95 % of all memberships, but introducing a small amount of per-group information dramatically improves our ability to model users belonging to multiple groups.

In the past, most researchers focused on the efficacy of tie-strength in various applications for both online and offline social networks. However, how tie-strength can help in the analysis of online social networks was a commonly neglected issue. The massive size and recording properties of online social networks offer the possibility to measure tie-strength objectively. In this study, we examine a social network extracted from a blog network. We then propose a tie-strength measurement and investigate several properties of the network using the tie-strength we defined. We also study how tie-strength

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