One-mode projection analysis and design of covert affiliation networks

Within the field of national security and counterterrorism a great need exists to understand covert organizations. To better understand these cellular structures we model and analyze these cells as a collection of subsets of all participants in the covert organization, i.e., as hypergraphs or affiliation networks. Such a covert affiliation network structure is analyzed by evaluating the one-mode projection of the corresponding hypergraph. First we provide a characterization of the total distance in the one-mode projection using its corresponding cell-shrunken version. Secondly we evaluate the one-mode projection with respect to the secrecy versus information tradeoff dilemma every covert organization has to solve. We present and analyze affiliation networks representing common covert organizational forms: star, path and semi-complete hypergraphs. In addition we evaluate an example of a covert organization wishing to conduct an attack and compare its performance to that of the common covert organizational forms. Finally we investigate affiliation networks that are optimal in the sense of balancing secrecy and information. We show how any affiliation tree can be improved by altering its structure. Finally we prove that among covert organizational forms in the class of hypertrees with the same number of cells uniform star affiliation networks are optimal.     

Mapping networks in corporate social responsibility communication on social media: A new approach to exploring the influence of communication tactics on public responses

Grounded in the networked stakeholder management theory and two-way communication, this study provides a snapshot of networks between companies and publics on Twitter in the context of corporate social responsibility (CSR) communication. Results showed that CSR communication activities (i.e., informing, retweeting, and mentioning) empowered a corporation through centralizing its network position and gaining public support (i.e., emotional, influencer, and knowledge support). In addition, degree centrality mediated the relationship between corporate retweets and stakeholder support and between corporate response and stakeholder support.     

Functional specificity in discussion networks: The influence of general and problem-specific networks on health outcomes

Though commonly used in social science research to measure the influence of social networks, the link between discussing “important matters” within networks and the achievement of instrumental ends is frequently unspecified or untested. To address this gap, we explore the consequences of using the general “important matters” approach versus one in which the substance of discussions is directly linked to the outcomes of interest. The egocentric social networks of people experiencing an acute health crisis are examined. We identify the characteristics of and the degree of membership overlap between “important matters” and “health matters” discussants, and explore their relative power in explaining a wide range of health and health services-related outcomes. We find no evidence for the influence of “important matters” networks, while characteristics of “health matters” networks demonstrate a significant effect across all models.     

Information communities: The network structure of communication

This study puts forward a variable clique overlap model for identifying information communities, or potentially overlapping subgroups of network actors among whom reinforced independent links ensure efficient communication. We posit that the average intensity of communication between related individuals in information communities is greater than in other areas of the network. Empirical tests show that the variable clique overlap model is indeed more effective in identifying groups of individuals that have strong internal relationships in communication networks relative to prior cohesive subgroup models; the pathways generated by such an arrangement of connections are particularly robust against disruptions of information transmission. Our findings extend the scope of network closure effects proposed by other researchers working with communication networks using social network methods and approaches, a tradition which emphasizes ties between organizations, groups, individuals, and the external environment.     

The gender structure of adolescent peer influence on drinking

The interactions of adolescent peers are the subject of both parental angst and scholarly attention. Peer influence is the most consistent predictor of adolescent drinking patterns when controlling for other background characteristics. This study extends these findings to incorporate a theoretical argument derived from status characteristics theory. Using 2980 best-friend dyads constructed from the National Longitudinal Study ofAdolescent Health ("Add Health"), I show that the peer influence process differs by the gender structure of the friendship. Adolescents in same-sex best friendships influence one another mutually, consistent with prior theoretical and empirical approaches to adolescent problem behavior: By contrast, boys in mixed-sex best friendships have influence over their female friends' drinking patterns, while the girls do not have any effect on their male friends' drinking behavior a finding consistent with status characteristics theory. The results indicate that peer influence models that do not take gender into account in the structure of the friendship misrepresent the unequal influence dynamics between boys and girls.     

The impact of computer based communication on the social structure of an emerging scientific specialty

This is a study of the impact of a computer conference on the formation of interpersonal ties among scientists. Various techniques from social networks analysis are adapted and used to study the structure of interpersonal ties among a set of scientists both before and during a computer conference. Although the data are not experimental, the results are suggestive. The computer, it seems, can perhaps take the place of protracted face-to-face interaction and provide the sort of social structure out of which a scientific specialty can grow.     

In search of a happy medium: How the structure of interorganizational networks influence community economic development strategies

Routes to economic development attract considerable attention among social scientists, policy makers, and community activists. Increasingly, social scientists examine various attributes of communities, their members, and their natural surroundings that facilitate and inhibit economic development. However, few empirical analyses exist that analyze the impact of a community's network structure on different forms of economic development such as on industrial recruitment and self-development. Using data collected from six communities in Washington State, the impact of a community's interorganizational network structure on industrial recruitment and self-development is examined. Results suggest that different types of network structures are better suited for different economic development strategies. A certain level of cohesiveness among community organizations and institutions are favorable for implementing self-development projects. However for industrial recruitment, networks that are bridging facilitate more types of economic development. While bonding and bridging network structures appear to be at odds with one another, it is possible for communities to increase both forms of economic development by maintaining a certain level of cohesiveness among subcomponents and increasing the number of organizations that serve as cut-points connecting non-redundant sources of information. These findings illustrate the need for communities and local activists to consider a community's network structure when deciding on an economic development strategy.     

The structure of online social networks mirrors those in the offline world

We use data on frequencies of bi-directional posts to define edges (or relationships) in two Facebook datasets and a Twitter dataset and use these to create ego-centric social networks. We explore the internal structure of these networks to determine whether they have the same kind of layered structure as has been found in offline face-to-face networks (which have a distinctively scaled structure with successively inclusive layers at 5, 15, 50 and 150 alters). The two Facebook datasets are best described by a four-layer structure and the Twitter dataset by a five-layer structure. The absolute sizes of these layers and the mean frequencies of contact with alters within each layer match very closely the observed values from offline networks. In addition, all three datasets reveal the existence of an innermost network layer at ∼1.5 alters. Our analyses thus confirm the existence of the layered structure of ego-centric social networks with a very much larger sample (in total, >185,000 egos) than those previously used to describe them, as well as identifying the existence of an additional network layer whose existence was only hypothesised in offline social networks. In addition, our analyses indicate that online communities have very similar structural characteristics to offline face-to-face networks.     

Guanxi networks and the gatekeeping practices of communication journals in China

In China, scholarly journals are affiliated with the particular governing organizations that house them. This process of what can be characterized as danweization has given the editors of these journals almost unchallenged power, prompting the contributors to seek their favor through guanxi networks. Drawing on fieldwork and in-depth interviews with key journal editors in media studies, this paper aims to explore the configuration of guanxi networks, the dynamics of guanxi practice in the gatekeeping process, and the implications of this practice for communication scholarship. We found that guanxi functions as a multi-layered particularism to facilitate the flow of information, to advance the priority of given papers, and to increase the rate at which such papers are published. In consequence, these journals publish a disproportionate number of articles by colleagues from the same sponsoring danwei. The operation of guanxi networks is so entrenched that it raises questions about the integrity of knowledge production and academic autonomy in China.     

Health and the structure of adolescent social networks

Much research has explored the role of social networks in promoting health through the provision of social support. However, little work has examined how social networks themselves may be structured by health. This article investigates the link between individuals' health and the characteristics of their social network positions. We first develop theoretical predictions for how health may influence the structure of adolescent networks. We then test these predictions using longitudinal analysis of the National Longitudinal Study of Adolescent Health (Add Health). We find important relationships between the health status of adolescents and the characteristics of the social network positions within which they are embedded. Overall we find that adolescents in poor health form smaller local networks and occupy less central global positions than their healthy peers. These results also have implications for social network research, expanding the scope of factors responsible for the network positions individuals occupy.     

The development of structure in random networks: an analysis of the effects of increasing network density on five measures of structure

The density of ingroup relations continues to be proposed as an indicator of structural cohesion. Network density is obviously a misleading indicator of structural cohesion when a group has subgroups; in such circumstances, the cohesion may be entirely internal to the subgroups. However, it is plausible that network density is a useful indicator of structural cohesion when it can be assumed that a group lacks subgroups. In order to analyze this possibility, I construct a set of random networks, increase the density of relations in these networks, and observe how the networks' structure develops in terms of five measures. The results show that low densities in large networks may be associated with more structural cohesion than higher densities in smaller networks; it is suggested that in field studies, attempts to control for network size will encounter problems of nonlinearity and heteroscedasticity. I conclude that network density is not a useful indicator of structure and that direct measurement of structure is to be preferred.     

Being of two minds: Ultimatum offers under cognitive constraints

We experimentally investigate how proposers in the Ultimatum Game behave when their cognitive resources are constrained by time pressure and cognitive load. In a dual-system perspective, when proposers are cognitively constrained and thus their deliberative capacity is reduced, their offers are more likely to be influenced by spontaneous affective reactions. We find that under time pressure proposers make higher offers. This increase appears not to be explained by more reliance on an equality heuristic. Analysing the behaviour of the same individual in both roles leads us to favour the strategic over the other-regarding explanation for the observed increase in offers. In contrast, proposers who are under cognitive load do not behave differently from proposers who are not.     

The influence of perceived shared risk in crisis communication: Elaborating the situational theory of publics

The study explored whether perceived shared experience with a media portrayal could influence various cognitions—such as concern, sense of personal involvement, and desire to learn more—that are important for behavior change. This research used the situational theory of publics in order to evaluate whether perceived shared risk is an antecedent to the factors leading to communication behavior. In general, the findings from this experiment supported the idea that shared risk experience with portrayals in news coverage has the potential to influence problem recognition, involvement recognition, and a new variable that combines information seeking and processing: that of information gaining.     

The use of sparsest cuts to reveal the hierarchical community structure of social networks

We show that good community structures can be obtained by partitioning a social network in a succession of divisive sparsest cuts. A network flow algorithm based on fundamental principles of graph theory is introduced to identify the sparsest cuts and an underlying hierarchical community structure of the network via maximum concurrent flow. Matula [Matula, David W., 1985. Concurrent flow and concurrent connectivity in graphs. In: Alavi, Y., et al. (Eds.), Graph Theory and its Applications to Algorithms and Computer Science. Wiley, New York, NY, pp. 543–559.] established the maximum concurrent flow problem (MCFP), and papers on divisive vs. agglomerative average-linkage hierarchical clustering [e.g., Matula, David W., 1983. Cluster validity by concurrent chaining. In: Felsenstein, J. (Ed.), Numerical Taxonomy: Proc. of the NATO Adv. Study Inst., vol. 1. Springer-Verlag, New York, pp. 156–166 (Proceedings of NATO ASI Series G); Matula, David W., 1986. Divisive vs. agglomerative average linkage hierarchical clustering. In: Gaul, W., and Schader, M. (Eds.), Classification as a Tool of Research. Elsevier, North-Holland, Amsterdam, pp. 289–301; Thompson, Byron J., 1985. A flow rerouting algorithm for the maximum concurrent flow problem with variable capacities and demands, and its application to cluster analysis. Master Thesis. School of Engineering and Applied Science, Southern Methodist University] provide the basis for partitioning a social network by way of sparsest cuts and/or maximum concurrent flow.     

The efficacy of tables versus graphs in disrupting dark networks: An experimental study

An agent tasked with disrupting a dark (covert and illegal) network must first be presented with information about the organization's structure. This paper uses a behavioral experiment to test in a stylized dark network disruption setting whether an agent makes a better disruption choice when the information is displayed in a table or a graph format. We find that subjects make decisions more quickly when presented with graphs, but that subjects perform weakly better with tables. An important lesson is that the display should explicitly distinguish non-existent links from potential links of unknown status.     

The spatial politics of the past unbound: transnational networks and the making of political identities

In this article I consider the relations between historical and contemporary forms of transnational political networks. I contest accounts that counterpose a networked present against a more settled and bounded past, arguing that this contrast rests on a problematic temporalization of difference in the construction of political identities. I consider how this temporalization produces particular accounts of relations between space, politics and identity. Drawing on the insurgent imaginative geography of resistance in C. L. R. James's The Black Jacobins, I argue for a focus on the dynamic geographies of connection formed through transnational networks. I develop this position through a discussion of the relations of the London Corresponding Society, formed in London in 1792, to transnational routes of political activists, organizational forms and ideas. This account highlights the multiple political identities crafted through transnational political networks. I conclude by outlining elements of a ‘usable past’ for contemporary counter‐global struggles.     

Common fate motivates cooperation: The influence of risks on contributions to public goods

In order to study whether common fate induced by shared risk can promote cooperation, I introduce two types of risks into a public goods game: risk that is common among all group members (the COM treatment), and risk that is independent across individuals (the IND treatment). In both treatments, zero contributions is the only equilibrium. In contrast to the equilibrium analysis, contributions to the public goods in the experiment approach zero under the independent risk but remain at high levels when the common risk is present. Analysis of the data reveals that different reactions to beliefs are fundamental to this treatment effect. While beliefs and contributions in the first periods, as well as the belief formation processes, are similar across treatments, subjects in the IND treatment are significantly less cooperative than those in the COM treatment with the same beliefs. A large variation in group contributions is observed in the COM treatment. Further analysis shows that initial beliefs can explain most of the variation in the long-run contribution level, implying the importance of beliefs in shaping the players’ experience and establishing group norms.     

Perceived leadership stability and the structure of urban agenda-setting networks

A number of recent studies have addressed the informal social structure surrounding urban decision making, showing its implications for collective political action. This paper extends these analyses by asking a prior question: what factors affect the structure of political networks? Specifically, the paper develops a model suggesting how one such factor, perceptions of political leadership and the expectations of political conflict they may engender, affect the structure of urban agenda-setting networks. Data collected from six cities show perceptions of leadership stability to be strongly correlated with four structural characteristics of these networks.     

Normalizing covert surveillance: the subterranean world of policing

In this article, I draw on data derived from an ethnographic field study of covert policing in the United Kingdom to demonstrate that the deployment of covert surveillance has become normalized, both in policing thought and operational practice. In a break with earlier patterns, the methods of covert surveillance are used extensively and are no longer regarded as a tactic of last resort. Covert policing is well anchored within organizational arrangements, empowered by a series of internal rationales mobilized to justify the expansion of covert tactics over and above more traditional, overt forms. The building of intrusive and exceptional policing practices within mundane contexts, I argue, is one of the ways the police have adapted to a broader policing environment characterized by public scepticism and distrust. Policing relies on the invisibility and low profile that comes with covert work, in order to govern contemporary concerns of crime and insecurity without the conflicts which can accompany – and trouble – overt policing practices. As mainstream policing becomes an increasingly extroverted enterprise, introverted forms of policing have come to the fore.