“For me, good network images help build our intuition about all those things that make networks special: the ability to see local detail embedded in macro structures, to distinguish intuitively those at the heart of a social system from those at the periphery, or to make clear the unstated schisms that divide social life. It is this ability to provide a richly contextualized micro-macro view that can span multiple dimensions that makes network visualizations worth the space.”

The gallery of 11 peer-reviewed visualizations includes a variety of visual approaches and networks, including those mapping political lobbying coalitions, Facebook friends, global trade, and in a visualization by ANN member and doctoral candidate Katya Ognyanova, the sharing of news topics among U.S. news media outlets. As Katya explains, “The research presented here proposes an exploration of inter-media agenda-setting. One of the big questions in the field is whether proliferation of channels and information overload have fragmented news content, rendering the idea of a consistent mainstream media agenda obsolete…The research demonstrates that mainstream media outlets not only have overlapping agendas at a given point in time, but also exhibit patterns of shared coverage that persist over time.”

For more on Katya’s visualization and the complete online symposium, go to: http://www.cmu.edu/joss/content/issues/vizsymposium.html

Tom Valente – network scientist, friend of ANN and professor at the USC Keck School of Medicine – has published a new paper written in collaboration with Kayo Fujimoto. A preprint of the article was recently released by the Social Networks journal.

From the paper:

“This paper proposes several measures for bridging in networks derived from Granovetter’s (1973) insight that links which reduce distances in a network are important structural bridges. Bridging is calculated by systematically deleting links and calculating the resultant changes in network cohesion (measured as the inverse average path length). The average change for each node’s links provides an individual level measure of bridging. We also present a normalized version which controls for network size and a network-level bridging index. Bridging properties are demonstrated on hypothetical networks, empirical networks, and a set of 100 randomly generated networks to show how the bridging measure correlates with existing network measures such as degree, personal network density, constraint, closeness centrality, betweenness centrality, and vitality. Bridging and the accompanying methodology provide a family of new network measures useful for studying network structure, network dynamics, and network effects on substantive behavioral phenomenon.”

Sinan Aral, Lev Muchnik andArun Sundararajan

ABSTRACT:

“Node characteristics and behaviors are often correlated with the structure of social networks over time. While evidence of this type of assortative mixing and temporal clustering of behaviors among linked nodes is used to support claims of peer influence and social contagion in networks, homophily may also explain such evidence. Here we develop a dynamic matched sample estimation framework to distinguish influence and homophily effects in dynamic networks, and we apply this framework to a global instant messaging network of 27.4 million users, using data on the day-by-day adoption of a mobile service application and users’ longitudinal behavioral, demographic, and geographic data. We find that previous methods overestimate peer influence in product adoption decisions in this network by 300–700%, and that homophily explains 50% of the perceived behavioral contagion. These findings and methods are essential to both our understanding of the mechanisms that drive contagions in networks and our knowledge of how to propagate or combat them in domains as diverse as epidemiology, marketing, development economics, and public health.”

Author: Matthew E., Brashears

Source: Social Networks, In Press, Corrected Proof, Available online 22 January 2010 (URL)

Abstract: This article evaluates the Durkheim/Berger argument that integration in a network of co-religionists protects against anomia. The 1985 General Social Survey network instrument is used to evaluate the effect of integration on anomia and the probability of unhappiness. Results indicate that contact with religiously homogeneous others paired with personal religious belief reduces anomia and the likelihood of unhappiness. Additionally, while ego/alter closeness is important, alter/alter closeness is not. These results suggest that individuals benefit from religious association more so than religious community. Additional analyses indicate that these results are unlikely to be due to homophily.

Yuan, Y. Connie,  Fulk, Janet,  Monge, Peter R.,  Contractor, Noshir

Communication Research 2010 37: 20-47

Just out in the new issue of Communication Research – an article combining social psychology and social network theory to explore transactive  memory processes.

Communication Research

Article abstract:
“Building on Kozlwoski and Klein’s emergence framework, this research developed and tested a set of multilevel hypotheses regarding individual and team transactive memory processes in work teams. Literature from social psychology suggested hypotheses on how shared task interdependence influences individual expertise exchange. Social network theory suggested hypotheses that individual expertise exchange is channeled according to communication tie strength. Using data collected from 218 individuals from 18 organizational teams, the proposed hypotheses were tested using hierarchical linear modeling techniques. The results showed that at the individual level the relationship between directory development and expertise exchange was mediated by communication tie strength and moderated by shared task interdependence.Team-level variables also were significantly related to individual-level outcomes such that individual expertise exchange happened more frequently in teams with well-developed team-level expertise directories, as well as with higher team communication tie strength and shared task interdependence.”

Elsevier

The Social Networks journal has published the first of its two special issues on network dynamcis: Dynamics of Social Networks edited by Patrick Doreian, Tom A.B. Snijders.

From the editors:

“This journal issue contains the first of two connected special issues on Dynamics of Social Networks. This second special issue will appear later this year. For a rather long time, attention to dynamic aspects in Social Network Analysis took the form of descriptive studies. However, over the last fifteen years model-based approaches to studying network change have been flowering. Landmarks were three special issues on Network Evolution of the Journal of Mathematical Sociology, edited by Frans Stokman and Patrick Doreian, in 1996 (with a book version: Doreian and Stokman, 1997 In: P. Doreian and F.N. Stokman, Editors, Evolution of Social Networks, Gordon and Breach Publishers, Amsterdam (1997).Doreian and Stokman, 1997), 2001, and 2003. These three special issues demonstrated how formal and statistical modeling and empirical analysis were coming together. The 2001 and 2003 special issues were focused on joining of theoretical developments with the analysis of empirical data using advanced modeling. This special issue presents a continuation of jointly using theories and modeling to understand social network phenomena.”

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The  September 2009 theme issue is titled “Social Networks and American Politics.” The issue draws on work presented at the first “Networks in Political Science” conference held at Harvard University in 2008 and co-chaired by David Lazer and James Fowler. In the introductory article, Michael T. Heaney and Scott D. McClurg write:

“…network analysis has expanded during the last decade within the study of American politics, contributing to knowledge about political institutions, behavior, and network theory. Promising directions for future research include the study of power, preference aggregation, information flow and transaction costs, and network dynamics.”

The issue features research on the influence of networks on political institutions and political behavior, the use of game theory and network theory to explain coordination problems, and the role of interdependence and density dependence in political networks.

The table of contents for the theme issue can be found here:

http://apr.sagepub.com/content/vol37/issue5/

James Moody announces the publishing of a new blog network paper by Carter Butts and Remy Cross in the Journal of Social Structure.

Journal of Social Structure

From the authors:

“This study examines global patterns of stability and change within six longitudinal samples of English-language weblogs (or “blogs”) during the 2004 U.S. Presidential election campaign. Using distance-based methods of graph comparison, we explore the evolution of the blog-blog citation networks for each sample during the period. In addition to describing the qualitative dynamics of the blog networks, we relate major campaign events (e.g., party political conventions and debates) to the observed pace of change. As we demonstrate, such events are associated with substantial differences in overall network volatility; moreover, volatility is also shown to have strong seasonal and endogenous components. Our findings suggest that external factors (both regular and episodic) may be important drivers of network dynamics.”

Paper abstract:

“Confidence is an essential ingredient of success in a wide range of domains including job performance, mental health, sports, business, and combat. Many authors have suggested that overconfidence–defined here as believing you are better than you are in reality–is advantageous because it serves to increase ambition, resolve, morale, persistence, and/or the bluffing of opponents. However, too much overconfidence can cause arrogance, market bubbles, financial collapses, policy failures, disasters, and wars, so it remains a puzzle how such a false belief could evolve or remain stable in a population of competing accurate beliefs. Here, we present an evolutionary model that shows overconfidence actually maximizes individual fitness and populations will tend to become overconfident, as long as the resources at stake during conflicts exceed twice the cost of competition. This is because overconfident individuals make more challenges when there is uncertainty about the strength of opponents (and thus the outcome of conflicts), while less confident individuals shy away from many conflicts they would win. Where the value of a prize is at least twice the cost of trying, overconfidence is the best strategy. The model suggests that the conditions under which humans would have evolved to have a “rational” unbiased view of their own capabilities are exceedingly rare, and it helps to explain why resource-rich environments can paradoxically create more conflict. Moreover, the fact that overconfident populations are evolutionarily stable may be one reason why overconfidence persists today in politics, business, and finance, even if it causes occasional disasters.”

Elsevier’s Social Networks journal has published a corrected proof of a paper written by Uwe Matzat and Chris Snijders comparing the quality of ego-network data collected online vs. offline.

Elsevier

Paper abstract:

“We analyze whether differences in kind and quality of ego-centered network data are related to whether the data are collected online or offline. We report the results of two studies. In the first study respondents could choose between filling out ego-centered data through a web questionnaire and being probed about their network in a personalized interview. The second study used a design in which respondents were allocated at random to either online or offline data collection. Our results show that the data quality suffers from the online data collection and the findings indicate that this is the consequence of the respondents answering “mechanically”. We conclude that network researchers should avoid to simply copy traditional network items into a web questionnaire. More research is needed about how new design elements specific for web questionnaires can motivate respondents to fill out network questions properly.”

Informaworld

In the last  issue of Communication Monographs Frank Tutzauer and  Benjamin Elbirt propose a new measure of centralization for networks characterized by path-transfer processes.

From the authors:

“This article proposes a new measure of network centralization and reports the results of a simulation designed to determine the sampling distribution of the proposed measure.
The measure is based on the information-theoretic concept of entropy and is appropriate for those networks in which traffic flows over paths and propagates by means of transference.Tables of critical values are constructed which allow the researcher to conduct tests of significance.”

“The structure of the paper is as follows: First, the example networks used in this article will be described. Following an overview of some of the key developments in the centrality and centralization literature, including Borgatti’s (2005) taxonomy, pathtransfer processes will be modeled stochastically and the centrality measure appropriate for such processes will be reviewed. This actor-based measure of centrality will then be used to construct a network-based measure of centralization. Next, a simulation will be conducted that will allow the constuction of tables of critical values.  Finally, the critical-value tables will be applied to the illustrative networks and a few concluding thoughts will be offered.”

From the introduction of the issue (Wolfram Kaiser):

Journal of Public Policy

“Given its complex multilevel governance structures, the European Union (EU) is an obvious focus for studying policy networks as informal coordination mechanisms between state and non-state or public and private actors. The importance of this research field has increased exponentially with the EU’s spatial expansion, its institutional deepening, its forays into new policy areas and its growing role as an international actor. Research on policy networks at first focussed on analysing changes in national political systems and policy-making in particular policy fields. This approach is now being applied more systematically and comprehensively to understanding the transformation of EU governance during the last decade.

[…] In analysing the role of policy networks in the EU, the contributors to this special issue do not take a simple pro or con position in the debate about whether networks play an important role in governance or constitute a new form of governance. In fact, the structures, activities and functions of networks in the EU appear to vary too much to allow for such sweeping generalisations. Collectively, the papers endorse theoretical and methodological pluralism and stay away from grand meta-theoretical battles. Instead, the special issue combines articles utilizing quantitative, formal social network analysis and more descriptive qualitative approaches to understanding different dimensions of networked European politics and transdisciplinary collaboration embracing both historical and contemporary analysis of EU governance.”

From the publisher’s  description:

Manuel Castells

We live in the midst of a revolution in communication technologies that affects the way in which people feel, think, and behave. The mass media (including web-based media), Manuel Castells argues, has become the space where political and business power strategies are played out; power now lies in the hands of those who understand or control communication.

Over the last thirty years, Castells has emerged as one of the world’s leading communications theorists. In this, his most far-reaching book for a decade, he explores the nature of power itself, in the new communications environment.

His vision encompasses business, media, neuroscience, technology, and, above all, politics. His case histories include global media deregulation, the misinformation that surrounded the invasion of Iraq, environmental movements, the role of the internet in the Obama presidential campaign, and media control in Russia and China.

In the new network society of instant messaging, social networking, and blogging – “mass self-communication” – politics is fundamentally media politics. This fact is behind a worldwide crisis of political legitimacy that challenges the meaning of democracy in much of the world. Deeply researched, far-reaching in scope, and incisively argued, this is a book for anyone who wants to understand the dynamics and character of the modern world.

Communication Power

“How could Manuel Castells have predicted that now is the time of the perfect storm? I do not know. But I do know that his new book coincides with the largest downturn in global economies since the 1930s, with the most important American election since the 1960s, with a most radical transformation of world politics in many generations, and with the most profound reevaluation of the lives of modern citizens, from what they value to how they communicate. We have become used to Castells’ careful scholarship and penetrating analyses but in this new book he cuts deeper into the heart of the matter. Sometimes he provides illuminating answers and where he cannot, he frames the questions that must be answered. This is a powerful and much needed book for a world in crisis.”
–Antonio Damasio

“Manuel Castells unites the mind of a social scientist with the soul of an artist. His trilogy took us to the edge of the millennium. This book takes us beyond to the critical crossroads of the 21st century, where technology, communication, and power converge.”
–Rosalind Williams, Director, Program on Science, Technology and Society, MIT

Harvard Networked Governance

“The idea for this special issue arose in conjunction with the first conference on “Networks in Political Science,” held at Harvard University, June 13-14, 2008. The conference was cochaired by David Lazer of Harvard University and James Fowler of the University of California, San Diego, and supported with a grant from the National Science Foundation, with John Scholz of Florida State University as the principal investigator. [...] This special issue publishes eight of the best articles from the conference that focused on American politics.”

Sandra Gonzalez-Bailona (2009), Social networks

Links play a twofold role on the web: they open the channels through which users access information, and they determine the centrality of sites and their visibility. This paper adds two factors to the analysis of links that aim to draw a parallel between the web and other offline interorganisational networks: the resources that the organisations publishing online are able to mobilise, and the status or public recognition of those organisations. Exponential random graph models (ERGMs) are used to analyse a sample of the web of about one thousand sites, showing that both the economic resources of the producers of the sites (a proxy to their wider pool of resources) and their presence in traditional news media (a proxy to their status) significantly increase their probability of receiving more links, and therefore, their centrality. This adds a sociologically relevant dimension to the analysis of the web that has been disregarded so far but that is crucial to understand the way it distributes visibility.

Huisman, M. (2009), Journal of Social Structure, 10(1).

Analysis of social network data is often hampered by non-response and missing data. Recent studies show the negative effects of missing actors and ties on the structural properties of social networks. This means that the results of social network analyses can be severely biased if missing ties were ignored and only complete cases were analyzed. To overcome the problems created by missing data, several treatment methods are proposed in the literature: model-based methods within the framework of exponential random graph models, and imputation methods. In this paper we focus on the latter group of methods, and investigate the use of some simple imputation procedures to handle missing network data. The results of a simulation study show that ignoring the missing data can have large negative effects on structural properties of the network. Missing data treatment based on simple imputation procedures, however, does also have large negative effects and simple imputations can only successfully correct for non-response in a few specific situations.

Pamela E. Carter, Gina Green(2009), Communications of the Association for Computing Machinery. Pages 105-109.

David Ronfeldt and Danielle Varda (2009), Social Science Research Network.

The deepening of the information age will alter the nature of the state so thoroughly that something new emerges: cyberocracy. While it is too early to say precisely what a cyberocracy will look like, the outcomes will include new kinds of democratic, totalitarian, and hybrid governments, along with new kinds of state-society relations. Thus, optimism about the information revolution should be tempered by an anticipation of its potential dark side. This paper reiterates the view of the cyberocracy concept as first stated in 1992, and then offers a postscript for 2008. It speculates that information-age societies will develop new sensory apparatuses, a network-based social sector, new modes of networked governance, and ultimately the cybercratic nexus-state as a successor to the nation-state.

Srikanth Paruchuri (2009)Organization science, Published online before print January 22, 2009.

This paper proposes that a mechanism through which a firm’s location in the interorganizational network influences the firm’s internal innovation activities is modifying the amount of information flowing within the firm. Exploring a firm’s internal innovation activities, I hypothesized that structural centrality of an inventor in the intrafirm co-inventing network is associated with her impact on her firm’s innovation activities in an inverted-U-shape relation. I further hypothesized that this relationship is moderated by the firm’s centrality and span of structural holes in the interfirm network. I found strong support for these hypotheses in a longitudinal study of eight large pharmaceutical firms. The findings in this paper, apart from having managerial implications, have implications for research on alliances, network studies, and innovation processes.

Andrew V. Shipilov (2009), Organization Science, January-February 2009; 20: 85 – 106.

This study investigates characteristics that affect the relationship between firms’ positions in a network of collaborative ties with other firms and their performance. Firms located in similarly structured networks rich in structural holes may obtain different performance results depending on their (1) capacity to absorb heterogeneous information, (2) ability to protect against partner noncooperation, and (3) bargaining power. In this paper, I argue that firms with a wide scope of experience have superior absorptive capacity for dealing with heterogeneous information; hence, such firms will be able to extract performance improvements from network positions rich in structural holes. Furthermore, firms with a high level of historic multimarket contact (MMC) with their partners are able to reduce the risks of partner noncooperation, hence augmenting their performance compared to firms in open networks that do not enjoy MMC with their own partners. Finally, firms of low centrality in the industry’s network of alliances will extract performance benefits from enhancing bargaining power as a result of exploiting brokerage opportunities in open networks. These arguments are corroborated in a study of relationships formed among investment banks’ advising on the merger and acquisition transactions in the United Kingdom between 1992 and 2001.