Exponential random graph models for multilevel networks

Advisors: Alan Polansky.Committee members: Sanjib Basu; Nader Ebrahimi.This master's thesis investigates the use of exponential random graph models for multilevel networks. It begins by describing some basic ideas in network analysis and then moves into the use of models to describe observed networks. After establishing modeling concepts for single-level networks, the discussion expands to modeling multilevel networks, which is a less common practice, and provides a brief multilevel modeling application. Focus is given to ERGM theory basics and highlights potential problems that researchers may encounter when employing these methods. Ultimately, the reader leaves with a sense of how and why network complexity can be modeled and some of the challenges that face network research.M.S. (Master of Science

The Ambivalence of Cultural Homophily: Field Positions, Semantic Similarities, and Social Network Ties in Creative Collectives

This paper utilizes a mixture of qualitative, formal, and statistical socio-semantic network analyses to examine how cultural homophily works when field logic meets practice. On the one hand, because individuals in similar field positions are also imposed with similar cultural orientations, cultural homophily reproduces objective field structure in intersubjective social network ties. On the other hand, fields are operative in practice and to accomplish pragmatic goals individuals who occupy different field positions often join in groups, creatively reinterpret the field-imposed cultural orientations, and produce cultural similarities alternative to the position-specific ones. Drawing on these emergent similarities, the cultural homophily mechanism might stimulate social network ties between members who occupy not the same but different field positions, thus contesting fields. I examine this ambivalent role of cultural homophily in two creative collectives, each embracing members positioned closer to the opposite poles of the field of cultural production. I find different types of cultural similarities to affect different types of social network ties within and between the field positions: Similarity of vocabularies stimulates friendship and collaboration ties within positions, thus reproducing the field, while affiliation with the same cultural structures stimulates collaboration ties between positions, thus contesting the field. The latter effect is visible under statistical analysis of ethnographic data, but easy to oversee in qualitative analysis of texts because informants tend to flag conformity to their positions in their explicit statements. This highlights the importance of mixed socio-semantic network analysis, both sensitive to the local context and capable of unveiling the mechanisms underlying the interplay between the cultural and the social.Comment: The latest version of this paper was accepted to Poetics in 201

The embeddedness of organizational performance: multiple membership multiple classification models for the analysis of multilevel networks

We present a Multiple Membership Multiple Classification (MMMC) model for analysing variation in the performance of organizational sub-units embedded in a multilevel network. The model postulates that the performance of organizational sub-units varies across network levels defined in terms of: (i) direct relations between organizational sub-units; (ii) relations between organizations containing the sub-units, and (iii) cross-level relations between sub-units and organizations. We demonstrate the empirical mer- its of the model in an analysis of inter-hospital patient mobility within a regional community of health care organizations. In the empirical case study we develop, organizational sub-units are departments of emergency medicine (EDs) located within hospitals (organizations). Networks within and across levels are delineated in terms of patient transfer relations between EDs (lower-level, emergency transfers), hospitals (higher-level, elective transfers), and between EDs and hospitals (cross-level, non-emergency transfers). Our main analytical objective is to examine the association of these interdependent and par- tially nested levels of action with variation in waiting time among EDs – one of the most commonly adopted and accepted measures of ED performance. We find evidence that variation in ED waiting time is associated with various components of the multilevel network in which the EDs are embedded. Before allowing for various characteristics of EDs and the hospitals in which they are located, we find, for the null models, that most of the network variation is at the hospital level. After adding these characteris- tics to the model, we find that hospital capacity and ED uncertainty are significantly associated with ED waiting time. We also find that the overall variation in ED waiting time is reduced to less than a half of its estimated value from the null models, and that a greater share of the residual network variation for these models is at the ED level and cross level, rather than the hospital level. This suggests that the covari- ates explain some of the network variation, and shift the relative share of residual variation away from hospital networks. We discuss further extensions to the model for more general analyses of multilevel network dependencies in variables of interest for the lower level nodes of these social structures

Interethnic Relations among Roma and Non-Roma Students in Hungary = Roma és nem roma tanulók interetnikus kapcsolatai

The thesis focuses on the positive and negative relations between Roma and non-Roma Hungarian students. Educational integration of Roma pupils is a widely researched topic in Hungary (Berényi, Berkovits, and Erőss 2008; Havas and Liskó 2005; Kertesi and Kézdi 2011; Kertesi and Kézdi 2009), but less is known about the relational integration of classmates of different ethnic background. This study aims to fill this gap and investigates the extent and quality of positive and negative relationships between Roma, constituting the largest ethnic minority group in Hungary, and non-Roma Hungarian students. To better understand the nature of ethnic classification, we also concentrate on the determinants of ethnic classification among secondary school students. Moreover, we examine both ethnic self-identification and peers’ perceptions of classmates’ ethnicity in our empirical analyses. ____ A disszertáció a roma és nem roma tanulók közötti pozitív és negatív kapcsolatokat vizsgálja. A roma tanulók iskolai szegregációját több kutatás is vizsgálta Magyarországon (Berényi, Berkovits, és Erőss 2008; Havas és Liskó 2005; Kertesi és Kézdi 2011; Kertesi és Kézdi 2009), azonban keveset tudunk arról, hogy az oktatási integráció megvalósulásával kialakulnak-e pozitív kapcsolatok a különböző etnikai hátterű tanulók között. Tanulmányunk ennek a kérdésnek a megválaszolására törekszik. Emellett az interetnikus kapcsolatok vizsgálatakor fontos kérdés az is, hogy az etnicitást hogyan definiáljuk. Tanulmányunkban nem csak a diákok etnikai önidentifikációját, hanem a társak általi klasszifikációt is bevonjuk az empirikus elemzésekbe, valamint arra a kérdésre is keressük a választ, hogy az etnikai klasszifikációt milyen tényezők befolyásolják

Status and Negative Ties: A Longitudinal Network Study among Adolescents = Státusz és negatív kapcsolatok: Egy longitudinális hálózatelemzés középiskolások körében

The PhD thesis examines how the negative, "dark side" of interpersonal relations and status positions interrelate among secondary school students in Hungary. Consequently, the thesis has two important goals. The first, the scientific aim is to measure and empirically analyze the interrelated dynamics of the negative relationships and the status positions of adolescents in secondary schools, using a Hungarian longitudinal dataset. The second, the practical aim of the project is to offer insights and incentives for policy makers, school psychologists and teachers in Hungary

Determinants in the formation of sociotechnical innovation networks : an inferential analysis using exponential graph models (ERGM)

Redes sociais face aos desafios num mundo global / coordenação [de] Joaquim Manuel Rocha Fialho, e outros. - Lisboa : Universidade Lusíada. 2023. - ISBN 978-989-640-249-5 - P. 61-73