When it comes to comprehension of complex phenomena, humans need to understand what interactions lie within them.These interactions are often captured with complex networks. However, the interaction pluralism is often shallowed by traditional network models. We propose a new way to look at these phenomena through the lens of multiplex networks, in which catalysts are drivers of the interaction through substrates. To study the entanglement of a multiplex network is to study how edges intertwine, in other words, how catalysts interact. Our entanglement analysis results in a full set of new objects which completes traditional network approaches: the entanglement homogeneity and intensity of the multiplex network, and the catalyst interaction network, with for each catalyst, an entanglement index. These objects are very suitable for embedment in a visual analytics framework, to enable comprehension of a complex structure. We thus propose of visual setting with coordinated multiple views. We take advantage of mental mapping and visual linking to present simultaneous information of a multiplex network at three different levels of abstraction. We complete brushing and linking with a leapfrog interaction that mimics the back-and-forth process involved in users' comprehension. The method is validated and enriched through multiple applications including assessing group cohesion in document collections, and identification of particular associations in social networks.

The purpose of this study is to demonstrate a practical application of social network analysis in the field of education using a large-scale data source. Using the Early Childhood Longitudinal Base Year data, a network is identified by examining the connections that occur between supports, both inside and outside formal special education resources for kindergarteners with access to special education programs. Social network mappings and quantitative findings are presented for formal and informal supports and primary disability category, along with policy implications and suggestions for further research. Findings indicate that social network analysis offers a unique and innovative perspective to educational research.

Individual shortcomings and the need for resources stimulates organizations desire to establish collaborative relations with each other. An organization tends to prefer to collaborate with other familiar organizations. The information available to an organization about its peers is necessary for its ability to appreciate the suitability of potential partners as well as their capabilities and ability to contribute to a successful collaborative relation. In a three stage analytical process, social network analysis and statistical network modelling is applied to investigate the correlation between patterns of communication and the extent to which organizations establish collaborative relationships. With a theoretical framework of resource dependence theory and social capital, data on information exchanges, resource exchanges and common advocacy among humanitarian 55 organizations is mapped. The first analytical stage explicates the structures of the collected information exchanges and evaluates the prevalence of coordination facilitating communication structures. The second stage appreciates the extent of inter-organizational involvement in collaborative relationships. The third step combines these results to demonstrate the covariance between the prevalence of coordination facilitating structures and extent of collaborative relations. The results indicate that the collected information exchanges exhibit few coordination facilitating structures and the organizations are only to a very limited extent engaged in collaborative relationships with each other. While consistent with previous research on the importance of communication for coordination, these observations illustrate the negative consequences of lacking communication. This analysis contributes with added empirical experiences to solidify our understanding of organizational behavior in inter-organizational interaction and tendencies to establish collaborative relations.

This dissertation has two overall aims; to explore and develop the use of SNA in sociology, and to demonstrate that sociology has much to give to other sciences. Interdisciplinary collaboration is necessary because we do not live in a world in which subject areas are strictly isolated. Human beings are social animals, and a sociological understanding is crucial in all human-related science. The examination in this thesis of different kinds of social networks and how they affect the lives of individuals (and vice versa) will provide knowledge both in the development of methods for analyzing social networks, and in their areas specific scientific areas. Paper I-III investigates sexual networks and how the number of sexual encounters involving intercourse in combination with the number of sexual partners affects the dynamics of sexually transmitted infections (STIs). The results show that this relationship is non-linear, indicating that it may not be the individuals with the largest number of partners who have the most impact on the spread of STIs. One might also have to focus interventions on individuals who have a large number of sexual encounters involving intercourse per partner, and who have several (but not necessarily a very large number of) partners. In the fourth paper, we apply the theoretical concept of so-called small worlds to a sexual network. The spread of epidemics can be difficult to stop in such networks, and we show that the sexual network of individuals infected with chlamydia can be characterized as such. The fifth and last paper differs from the four first. In this paper, we focus on how individuals who committed suicide in Stockholm during the 1990s where connected to each other. The social-interaction exposure effect is larger for the individual within the family than at the workplace; yet work-domain exposure is more important for the overall suicide rate because individuals are more often exposed to suicides of co-workers than family members.

In this thesis we propose semantic-social recommendation algorithms, that recommend an input item to users connected by a collaboration social network. These algorithms use two types of information: semantic information and social information.The semantic information is based on the semantic relevancy between users and the input item; while the social information is based on the users position and their type and quality of connections in the collaboration social network. Finally, we use depth-first search and breath-first search strategies to explore the graph.Using the semantic information and the social information, in the recommender system, helps us to partially explore the social network, which leads us to reduce the size of the explored data and to minimize the graph searching time.We apply our algorithms on real datasets: MovieLens and Amazon, and we compare the accuracy an the performance of our algorithms with the classical recommendation algorithms, mainly item-based collaborative filtering and hybrid recommendation.Our results show a satisfying accuracy values, and a very significant performance in execution time and in the size of explored data, compared to the classical recommendation algorithms.In fact, the importance of our algorithms relies on the fact that these algorithms explore a very small part of the graph, instead of exploring all the graph as the classical searching methods, and still give a good accuracy compared to the other classical recommendation algorithms. So, minimizing the size of searched data does not badly influence the accuracy of the results.

Diplomatic summits serve as critical opportunities for national leaders to interact and mobilize the political will needed to address the world’s greatest challenges. Yet, summits have a checkered past with both successes and failures. Consequently, summit diplomacy has been equated with highly publicized photo opportunities for heads of government and grandiose communiqués with vague commitments that are never fully realized. Due to concerns about their effectiveness, legitimacy, and representation, summits are in a period of transition. These trends and challenges are especially evident in the G8, and scholars have recognized that the G8 summit has evolved to include more actors than the past. Although acknowledged as a potential site of networked governance, empirical evidence of such activity is limited. Research has yet to identify the actors involved, the structures of the relationships, and the impact of networked approaches on the preparatory process. This research specifically explores the question of how a global level network affects the priorities adopted by the G8. Using the 2010 G8 Summit as a case to examine the increased prevalence of networked activity, this study focuses on the Summit’s signature initiative: maternal, newborn and child health (MNCH). MNCH is a longstanding global problem and despite efforts such as the Millennium Development Goals, poor health outcomes persist in regions throughout the world. But to understand the selection and shaping of MNCH as the signature initiative of the 2010 G8 Summit, a mixed method approach is used. Social network analysis provides a detailed description of the actors involved in networked governance in summit diplomacy for the G8, and the structure of their relationships with one another. Qualitative data analysis of 63 in depth interviews of network members illuminates the rich and varied perspectives of the participants, which yields insight about why and how actors engage each other in order to achieve individual and collective goals. The study demonstrated that networked governance contributed to the political prioritization and substantive policy content of summit agenda items, determined during the 2010 G8 Summit preparatory process. In the case of MNCH, while the network was found to include of a diverse range of state and non-state actors, a core group of bureaucratic, political, and NGO actors played a prominent role in the selection and shaping of the MNCH initiative. Yet, the role, values and contributions of actors within the network were contested by network members during the preparatory process, demonstrating that shared goals and norms were not a dominant feature of the network. Moreover, the networked governance process has not entirely escaped the confines of geographical boundaries, given the most central actors in the network met face-to-face on a regular basis and were located in close geographical proximity. Actors from regions where MNCH problems persist most severely remained marginalized in the networked approach. While financial capital is an essential ingredient for the MNCH programs and interventions proposed for the G8 initiative, social capital was a neglected factor that is critical for building the capacity to generate new ideas and solutions. Actors within the 2010 G8 preparatory network for MNCH adopted various strategies to build and mobilize social capital. Specifically, a group of Canadian-based NGOs and an international organization formed a coalition in order to strategically advance the MNCH issue on the summit agenda. Conversely, government actors did not invest in developing and mobilizing social capital. Ultimately, informal strategies proved more valuable for breaking down hierarchical barriers and exerting influence than formal processes designed by government. Networked governance was a key factor that contributed to the political prioritization and shaping of the MNCH signature initiative for the 2010 G8 Summit and increased the inclusiveness of the summit’s preparatory process. However, while important, networked governance was not sufficient to fully explain the final outcomes – other factors such as domestic and global political contexts and the characteristics of the MNCH issue influenced the process and outcomes. Moreover, G8 summit diplomacy moved beyond being solely a state-based process in the case of MNCH, but the presence of a network of interconnected actors did not equate to better problem-solving. Although scholars and practitioners agree that integrated horizontal and vertical approaches are required for addressing the complexity of MNCH challenges, the networked approach failed to enable a move beyond conventional solutions to address the systemic nature of MNCH challenges. The findings of the study have important implications for policy and governance processes, where widespread cooperation among a network of state and non-state actors will be required for resolving intractable global problems.

The European Union (EU) is the most far-reaching attempt yet undertaken to institutionalize democratic policy-making beyond the nation-state. To what extent, and in what ways, do various channels of representation contribute towards the realization of this aim? This dissertation takes stock of current research on the EU’s system of representation, and seeks to expand its agenda so that this central question can be properly addressed. In contrast to prior empirical work in the field, the dissertation employs research designs that incorporate several forms of representation into a unified evaluative framework. This multi-channel approach to political representation paves the way for a systematic comparison of how different forms of representation (electoral, territorial and corporate) perform in the EU context. It also makes possible an empirical assessment of a key proposition in current representation theory: that elections, in large and heterogeneous political systems, are outperformed by other forms of representation. The three articles in the dissertation draw on existing cross-country data, interviews with policy-makers and a new dataset collected by the author. They scrutinize representation in three principal channels: electoral representation in the European Parliament, government representation in the preparatory bodies of the Council of Ministers, and representation through organized interests that seek to influence EU policy. The first article examines the balance of power that has emerged between these three channels of representation in the EU’s legislative process, and how the current balance is likely to affect the Union’s legitimacy. The second article investigates how different channels of representation perform in terms of providing linkage between Brussels-based representatives and their domestic principals. The third article examines the extent to which different channels of representation contribute to the coordination of EU policy-making domestically, at the European level, and across the two levels of government. Finally, this dissertation makes a methodological contribution by applying social network analysis (SNA) to classic problems of representation within and across different channels of representation. This approach is novel to the field. Researchers should be able to exploit SNA and relational data fruitfully in the future, in the study of representational relationships in the EU and numerous other contexts.

abstract: The purpose of this study was to explore features of Supplemental Educational Services (SES) implementation at the district level. In the study beliefs, goals, and actions of district office administrators were analyzed against the backdrop of changing federal guidelines and challenges faced by SES implementers across Arizona. The case study focuses on implementation in the 2007-2008, 2008-2009, and 2009-2010 school years. The study uses the 2005 and 2009 Department of Education guidelines, survey responses from Arizona district and school implementers, as well as documents and interviews from an urban Arizona case district. The study separates the implementation activities into task areas, which are analyzed separately. Using a loose coupling perspective, the separate task areas are furthered used as coupling domains and represented in social network graphs. Results show that the case district personnel were highly focused on their primary role, maintaining district compliance with federal guidelines. The district personnel employed several changes over the case study period to centralize their control of SES operations within district. The employment and training of site level coordinators was the most impactful of the strategies. As boundary spanners, the coordinators allowed greater access to information, oversight, and influence at the site level. Despite the growing capacity and earnest efforts of the district personnel, the case district was still very far from being able to measure or assess the impact of SES on student achievement. Centralization in the scholastic task areas was relatively low, and had marginal changes over the case study period. Years into the program, there was still no avenue to accurately gauge the effectiveness. As the district personnel were chiefly concerned with compliance, they had suspended judgment on the program and focused primarily on improving their processes. / Dissertation/Thesis / Ph.D. Educational Leadership and Policy Studies 2011

A presente tese tem por objetivo identificar estruturas e dinâmicas associadas à circulação de diferentes tipos de acontecimentos jornalísticos no Twitter. Busca-se, com isso, comparar as formas de circulação de narrativas em torno de diferentes tipos de acontecimentos jornalísticos em sites de rede social. Tem-se como pressuposto o fato de que o jornalismo contemporâneo estaria configurado como uma rede, formada por nós compostos por diversos atores para além dos veículos jornalísticos, os quais, através da participação de variadas formas, contribuem para a circulação jornalística. O referencial teórico do trabalho aborda o paradigma de redes, a circulação na cibercultura e no jornalismo, as especificidades da circulação e da recirculação jornalística em sites de rede social e o acontecimento jornalístico. Para operacionalizar a pesquisa, utiliza-se como método o estudo de caso de postagens no Twitter em torno de determinados acontecimentos jornalísticos associados à Copa do Mundo de 2014. Ao todo quatro casos são estudados tendo como procedimentos metodológicos a observação e a análise de redes sociais. Os resultados trazem indícios de que a participação do público na circulação jornalística traz modificações não apenas para o jornalismo como também pode provocar ressignificações no próprio acontecimento. / In this thesis, we aim to identify structures and dynamics associated to the circulation of different types of news events on Twitter. Thus, we seek to compare forms of circulation of narratives about different types of news events in social network sites. One of the premises we adopt is the fact that contemporary journalism is shaped like a network, composed by nodes that comprises diverse actors beyond news outlets, which, through participation in various forms, contribute to news circulation. We use as a theoretical background concepts related to the network paradigm, to circulation of contents on cyberculture and journalism, the specificities of news circulation and recirculation in social network sites, and news events. In order to operationalize the research, we use the method of case study of posts on Twitter about some specific news events related to the 2014 FIFA’s World Cup. We studied four cases using a combination of observation and social network analysis. The results provide evidence that the participation of the public on news circulation brings changes not only for journalism but also leads to a reframing in the events themselves.

Este estudo teve como objetivo principal identificar as redes de conhecimento, que os professores de Ciências da escola básica formaram na escolha e uso de fontes de informação durante a formação acadêmica e na tomada de decisão para a elaboração do planejamento de ensino. Os procedimentos metodológicos se relacionaram a uma abordagem mista, a partir das ferramentas da Análise de Redes Sociais (ARS), que permitiu o mapeamento e a caracterização das relações existentes, sob a forma de um estudo de caso, que incluiu a aplicação de um questionário, realizado com os professores de Ciências da rede municipal de Cachoeirinha, RS, que atuam na educação básica com alunos dos anos finais no ensino fundamental. Os dados foram analisados com o uso dos softwares UCINET e NetDraw, que possibilitou a partir dos resultados revelar alguns padrões estruturais de relacionamento dos professores com as fontes em forma de rede. A fundamentação teórica desta pesquisa perpassa por autores que estudam o conceito da sociedade em rede, o ensino de ciências, as novas tecnologias e as fontes de informação no ensino. Investigou-se ainda de que forma as fontes de informação podem contribuir para o desenvolvimento do Ensino de Ciências na educação básica. Os resultados indicaram que a fonte mais utilizada durante a formação acadêmica foram as Bibliotecas e no planejamento de ensino são os livros didáticos, seguido do buscador Google.com e de jornais. Verificou-se que a escolha do professor pelo uso de determinada fonte de informação está relacionada com os recursos pedagógicos tradicionais usados no processo de ensinar e aprender e também com a visão de educação que os professores possuem. Conclui-se o estudo ao salientar o desafio da prática pedagógica, a necessidade da formação continuada dos professores em consonância com as novas tecnologias educacionais para dar conta da realidade social do aluno e avançar no processo de ensinar e apreender no âmbito das Ciências, Tecnologia e Sociedade (CTS). / This study aimed to identify the knowledge networks, the basic school science teachers formed in the choice and use of information sources during the academic and decision-making for the development of educational planning. The methodological procedures were related to a mixed approach, from the Social Network Analysis tools (SNA), which allowed the mapping and characterization of the relationship, in the form of a case study, which included a questionnaire performed with the science teachers in the municipal Cachoeirinha, RS, working in primary education with students of final years in elementary school. Data were analyzed with the use of UCINET and NetDraw software, which allowed from the results reveal some structural patterns teacher relationship with sources in network order. The theoretical basis of this research permeates authors who study the concept of the network society, science education, new technologies and information sources in teaching. Were also investigated how the information sources can contribute to the development of science education in basic education. The results indicated that the source used most during the academic training were Libraries and education planning are textbooks, followed by Google.com search engine and newspapers. It was found that the choice of the teacher by the use of a particular source of information is related to the traditional teaching resources used in the process of teaching and learning and also with the vision of education that teachers have. We conclude the study to highlight the challenge of teaching practice, the need for ongoing training of teachers in line with the new educational technologies for dealing with the social reality of the student and support the process of teaching and seize.