Sunbelt XXXI International Network for Social Network ... - INSNA

Viable And Non‐viable Models Of Cross‐sectional And Longitudinal Network DataSchweinberger, MichaelExponential Random GraphsStatistical Methods, ERGM/P*, Simulation, Statistical Models, Sensitivity Analysis, Longitudinal Social NetworkSUN.AM1It is well‐known (Frank and Strauss, 1986, Wasserman and Pattison, 1996) that models of network dependence were inspired by models of spatial dependencein statistical physics and spatial statistics, e.g., the Ising model (Ising, 1925). Less well‐known is that the Ising model and more general models need to satisfystability conditions to ensure meaningful, physical behavior. We argue that some of the same stability conditions need to be satisfied by models of networkdependence. Models which do not satisfy stability conditions suffer, in general, from excessive sensitivity and near‐degeneracy, and in special cases, the subsetof the parameter space corresponding to non‐degenerate distributions is a linear subspace of the full parameter space. These characteristics of unstablemodels hamper both simulation and statistical inference. We give a wide range of examples, including the Markov models of Frank and Strauss (1986) and thecurved exponential family models of Snijders et al. (2006) and Hunter and Handcock (2006). We discuss the extension of these results to longitudinal networkmodels, including the discrete‐time Markov model of Hanneke et al. (2010) and the continuous‐time Markov model of Snijders (2001).Virtual Brokerage And Closure: Assessing Player Social Capital In A Massively Multiplayer Online GameShen, Cuihua; Monge, Peter; Williams, DmitriOnline Social NetworksOn‐line Communities, Social Capital, Structural Holes, Brokerage, On‐line Game, ClosureTHURS.AM1Recent years have witnessed growing scholarly interest in evaluating the implications of internet and various social media on the creation and maintenance ofsocial capital. This study takes a structural approach to examine the effects of bridging and bonding social capital as network brokerage and closure. Takingadvantage of a unique dataset with both server logs and user survey over a nine‐month period, this study constructed social networks among players ofEverQuest II, a large Massively Multiplayer Online Game, and examined the effects of virtual brokerage and closure on task performance and trust. It illustratesan alternative way to define and operationalize online social capital structurally, and also contributes to the literature on the tension between bridging andbonding and their respective effects on instrumental and socioemotional goals in contemporary media environments. In addition, this study shows thatrelations established in virtual worlds may still demonstrate the same brokerage and closure effects originally found in offline social worlds, thus providinginitial construct‐validity evidence that virtual world networks can be used as parallel for understanding real world social dynamics.