Building models for social space: neighourhood-based models for social networks and affiliation structures

We propose a quantitative relational framework for social space. We suggest that social space cannot be specified simply in geographical, network or sociocultural terms but, rather, requires an understanding of the interdependence of relationships among different types of social entities, such as persons, groups, sociocultural resources and places. We also suggest that social space cannot be regarded as fixed: unlike the Euclidean space of Newtonian mechanics, social space is constructed, at least in part, by the social processes that it supports. In the general stochastic relational framework that we propose, relationships among social entities are regarded as the fundamental elements of social space and observed relational entities are viewed as the outcome of processes that occur in overlapping local relational neighbourhoods. Each neighbourhood corresponds to a subset of possible relational entities and is conceived as a possible site of social interaction. We show how special cases of this framework yield hierarchies of models for social networks and for affiliation structures. We also sketch some next steps in the development of this framework.Nous proposons un cadre pour une analyse quantitative relationnelle de l’espace social. Nous suggérons que l’espace social ne peut pas être défini simplement en termes géographiques ou socio-culturels mais que cette définition suppose de comprendre l’interdépendance entre différents types d’entités sociales telles que des personnes, des groupes, des ressources et des positions socio-culturelles. Nous suggérons également que l’espace social ne peut pas être vu comme figé : à la différence de l’espace euclidien de la mécanique newtonienne, l’espace social est construit au moins en partie par le processus social dont il est le support. Dans le modèle stochastique général que nous proposons, les relations entre entités sociales sont considérées comme les éléments fonda-mentaux de l’espace social et les échanges observés sont conçus comme les produits de processus qui agissent dans des voisinages relationnels qui se recouvrent. Chaque voisi-nage correspond à un ensemble d’entités rela-tionnelles et est conçu comme un lieu d’interactions sociales. Nous montrons comment des spécifications particulières de ce cadre théorique produisent des hiérarchies de modèles pour les réseaux sociaux et pour les structures d’affiliation. Nous évoquons également de futurs développements de ce cadre

Recent developments in exponential random graph (p*) models for social networks

This article reviews new specifications for exponential random graph models proposed by Snijders, Pattison, Robins & Handcock (2006) and demonstrates their improvement over homogeneous Markov random graph models in fitting empirical network data. Not only do the new specifications show improvements in goodness of fit for various data sets, they also help to avoid the problem of near-degeneracy that often afflicts the fitting of Markov random graph models in practice, particularly to network data exhibiting high levels of transitivity. The inclusion of a new higher order transitivity statistic allows estimation of parameters of exponential graph models for many (but not all) cases where it is impossible to estimate parameters of homogeneous Markov graph models. The new specifications were used to model a large number of classical smallscale network data sets and showed a dramatically better performance than Markov graph models. We also review three current programs for obtaining maximum likelihood estimates of model parameters and we compare these Monte Carlo maximum likelihood estimates with less accurate pseudo-likelihood estimates. Finally we discuss whether homogeneous Markov random graph models may be superseded by the new specifications, and how additional elaborations may further improve model performance

A spatial model for social networks

We study spatial embeddings of random graphs in which nodes are randomly distributed in geographical space. We let the edge probability between any two nodes to be dependent on the spatial distance between them and demonstrate that this model captures many generic properties of social networks, including the ``small-world'' properties, skewed degree distribution, and most distinctively the existence of community structures.Comment: To be published in Physica A (2005

Ethical Use and Impact of Participatory Approaches to Research in Post-Disaster Environments: An Australian Bushfire Case Study

Copyright © 2018 L. Gibbs et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.This paper presents a case study of Beyond Bushfires, a large, multisite, mixed method study of the psychosocial impacts of major bushfires in Victoria, Australia. A participatory approach was employed throughout the study which was led by a team of academic investigators in partnership with service providers and government representatives and used on-site visits and multiple methods of communication with communities across the state to inform decision-making throughout the study. The ethics and impacts of conducting and adapting the approach within a post-disaster context will be discussed in reference to theories and models of participatory health research. The challenges of balancing local interests with state-wide implications will also be explored in the description of the methods of engagement and the study processes and outcomes. Beyond Bushfires demonstrates the feasibility of incorporating participatory methods in large, post-disaster research studies and achieving rigorous findings and multilevel impacts, while recognising the potential for some of the empowering aspects of the participatory experience to be reduced by the scaled-up approach

Comparison of three methods for ascertainment of contact information relevant to respiratory pathogen transmission in encounter networks

<p>Abstract</p> <p>Background</p> <p>Mathematical models of infection that consider targeted interventions are exquisitely dependent on the assumed mixing patterns of the population. We report on a pilot study designed to assess three different methods (one retrospective, two prospective) for obtaining contact data relevant to the determination of these mixing patterns.</p> <p>Methods</p> <p>65 adults were asked to record their social encounters in each location visited during 6 study days using a novel method whereby a change in physical location of the study participant triggered data entry. Using a cross-over design, all participants recorded encounters on 3 days in a paper diary and 3 days using an electronic recording device (PDA). Participants were randomised to first prospective recording method.</p> <p>Results</p> <p>Both methods captured more contacts than a pre-study questionnaire, but ascertainment using the paper diary was superior to the PDA (mean difference: 4.52 (95% CI 0.28, 8.77). Paper diaries were found more acceptable to the participants compared with the PDA. Statistical analysis confirms that our results are broadly consistent with those reported from large-scale European based surveys. An association between household size (trend 0.14, 95% CI (0.06, 0.22), <it>P </it>< 0.001) and composition (presence of child 0.37, 95% CI (0.17, 0.56), <it>P </it>< 0.001) and the total number of reported contacts was observed, highlighting the importance of sampling study populations based on household characteristics as well as age. New contacts were still being recorded on the third study day, but compliance had declined, indicating that the optimal number of sample days represents a trade-off between completeness and quality of data for an individual.</p> <p>Conclusions</p> <p>The study's location-based reporting design allows greater scope compared to other methods for examining differences in the characteristics of encounters over a range of environments. Improved parameterisation of dynamic transmission models gained from work of this type will aid in the development of more robust decision support tools to assist health policy makers and planners.</p

Influence of Contact Definitions in Assessment of the Relative Importance of Social Settings in Disease Transmission Risk

BACKGROUND: Realistic models of disease transmission incorporating complex population heterogeneities require input from quantitative population mixing studies. We use contact diaries to assess the relative importance of social settings in respiratory pathogen spread using three measures of person contact hours (PCH) as proxies for transmission risk with an aim to inform bipartite network models of respiratory pathogen transmission. METHODS AND FINDINGS: Our survey examines the contact behaviour for a convenience sample of 65 adults, with each encounter classified as occurring in a work, retail, home, social, travel or "other" setting. The diary design allows for extraction of PCH-interaction (cumulative time in face-face conversational or touch interaction with contacts)--analogous to the contact measure used in several existing surveys--as well as PCH-setting (product of time spent in setting and number of people present) and PCH-reach (product of time spent in setting and number of people in close proximity). Heterogeneities in day-dependent distribution of risk across settings are analysed using partitioning and cluster analyses and compared between days and contact measures. Although home is typically the highest-risk setting when PCH measures isolate two-way interactions, its relative importance compared to social and work settings may reduce when adopting a more inclusive contact measure that considers the number and duration of potential exposure events. CONCLUSIONS: Heterogeneities in location-dependent contact behaviour as measured by contact diary studies depend on the adopted contact definition. We find that contact measures isolating face-face conversational or touch interactions suggest that contact in the home dominates, whereas more inclusive contact measures indicate that home and work settings may be of higher importance. In the absence of definitive knowledge of the contact required to facilitate transmission of various respiratory pathogens, it is important for surveys to consider alternative contact measures

Identification of five fundamental implicit theories underlying cognitive distortions in child abusers : a preliminary study

Qualitative analysis of interviews with 22 child abusers found strong evidence for Ward and Keenan\u27s (1999) proposal that there are five implicit theories in child abusers that account for the majority of their cognitive distortions/thinking errors. These implicit theories are: Child as a sexual being where children are perceived as being able to and wanting to engage in sexual activity with adults and also are not be harmed by such sexual contact; Nature of harm where the offender perceives that sexual activity does not cause harm (and may in fact be beneficial) to the child; Entitlement where the child abuser perceives that he is superior and more important than others: and hence is able to have sex with whoever, and whenever, he wants; Dangerous world where the offender perceives that that others are abusive and rejecting and he must fight to regain control; and Uncontrollable where the offender perceives the world as uncontrollable and hence he believes that circumstances are outside of his control. There was no evidence for any other type of implicit theory. Results of the study also indicated that there was a significant difference in terms of the endorsement of the Dangerous world implicit theory between participants reporting a history of child sexual abuse and those who did not. Offenders against male victims were significantly more likely to endorse the Child as a sexual being and Dangerous world implicit theories compared to men who had offended against female children