Orientador: Marcelo El Khouri Buzatto / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Estudos da Linguagem / Made available in DSpace on 2018-08-22T03:08:33Z (GMT). No. of bitstreams: 1 Gallardo_BarbaraCristina_D.pdf: 2620852 bytes, checksum: 55c3f4a997a603c243eaeb09adf2b394 (MD5) Previous issue date: 2013 / Resumo: O estudo parte da hipótese de que, na atualidade, o contato digital transnacional pode desenvolver a competência intercultural dos sujeitos, oportunizando a sua participação em letramentos e eventos sociodiscursivos autêntica, em contextos discursivos mais amplos que os possíveis no seu cotidiano off-line. Tomando como desejáveis e potencialmente inovadoras essas oportunidades no âmbito da formação de futuros professores de inglês, o estudo teve como objetivos primeiro, analisar as representações da identidade nacional constituídas no contexto dessas interações mediadas por computador e, segundo, investigar as principais facilidades e barreiras impostas pelo software escolhido para o estabelecimento e continuidade dessas relações transnacionais. Três estudantes brasileiras de Letras, de uma universidade estadual da região centro-oeste do Brasil estabeleceram contato com adultos estrangeiros no Facebook e com eles interagiram em língua inglesa por um período de seis meses, sob observação não-participante da pesquisadora. O corpus foi constituído do registro dessas interações, colhidos periodicamente pelos próprios sujeitos, totalizando 9.320 palavras. Para triangulação, foram consideradas transcrições de 3 horas de entrevistas semiestruturadas feitas com as participantes brasileiras e resultados de questionários aplicados preliminarmente às observações. Utilizou-se a Análise Crítica do Discurso (ACD) para desvendar a organização linguística e ideológica dos discursos nacionais acionados na transição para o contexto (interlocutor) transnacional online. Adicionalmente, utilizou-se o modelo de identidade social de efeitos de desindividuação (SIDE) para identificar visões estereotipadas e de identidades coletivas envolvidas nessas interações online. Os resultados sugerem a hibridação de estratégias do discurso de contextos off-line com os recursos multimodais dos contextos online. Em seus discursos identitários, os sujeitos adotaram estereótipos oriundos de centros geradores das dinâmicas de globalização, tanto em escala regional (sudeste do Brasil) como em escala mundial (os EUA). A falta de criticidade verificada no discurso no contexto estudado aponta a necessidade de projetos que articulem uma educação para a globalização não unilateral com a educação em línguas estrangeiras na formação do professor e do cidadão / Abstract: This study was developed under the assumption that, currently, transnational digital contact can develop intercultural competence, providing opportunities for people's participation in authentic literacy and sociodiscursive events in discursive contexts wider than those possible in offline contexts. Taking as desirable and potentially innovative these opportunities in the education of future English teachers, the study aimed first, to analyze representations of national identity in the context of these computer-mediated interactions and, second, to investigate the main facilities and barriers imposed by the software chosen for the establishment and continuity of these transnational relations. Three Brazilian students from a Liberal Arts course at a state university in the Midwest of Brazil established contact with foreigner adults on Facebook and interacted with them in English for six months under non-participant observation of the researcher. The corpus consisted of the register of these interactions, collected basically by the subjects themselves, with a total 9.320 words. For the triangulation of data it was considered transcripts of three hours of semi-structured interviews with Brazilian participants and preliminary results of questionnaires answered before the observation. A Critical Discourse Analysis (CDA) approach was used to unveil linguistic organization and ideological reproduction of national speeches in the transition to the online international context (interlocutor). Principles of the social identity model of deindividuation effects (SIDE) were additionally used to identify stereotypes and collective identities involved in these online interactions. The results suggest a hybridization of discourse strategies taken from both offline contexts and online contexts with its multimodal resources. The participants used stereotypes in their speeches that come from big cities where globalization dynamics are generated, both at a regional scale (southeastern Brazil) and worldwide (the U.S.A.). The lack of critical views verified in the discourse and context observed indicates the need for projects that articulate an education for non-unilateral globalization and an education for foreign language teachers and citizens / Doutorado / Linguagem e Tecnologia / Doutora em Lingüística Aplicada

Submitted by Renata Lopes (renatasil82@gmail.com) on 2015-12-01T13:50:34Z No. of bitstreams: 1 crystiamkellepereiraesilva.pdf: 5368190 bytes, checksum: 22e15248de5dbc282e6d4324b03dca64 (MD5) / Made available in DSpace on 2015-12-01T13:50:34Z (GMT). No. of bitstreams: 1 crystiamkellepereiraesilva.pdf: 5368190 bytes, checksum: 22e15248de5dbc282e6d4324b03dca64 (MD5) Previous issue date: 2015-03-27 / Existem inúmeros recursos educacionais distribuídos em diferentes repositórios que abordam um conjunto amplo de assuntos e que possuem objetivos educacionais distintos. A escolha adequada desses recursos educacionais é um desafio para os usuários que desejam usá-los para a sua formação intelectual. Nesse contexto surgem os Sistemas de Recomendação para auxiliar os usuários nessa tarefa. Para que seja possível gerar recomendações personalizadas, torna-se importante identificar informações que ajudem a definir o perfil do usuário e auxiliem na identificação de suas necessidades e interesses. O uso constante e cada vez mais intenso de algumas ferramentas tecnológicas faz com que inúmeras informações a respeito do perfil, dos interesses, das preferências, da forma de interação e do comportamento do usuário possam ser identificadas em decorrência da interação espontânea que ocorre nesses sistemas. Esse é o caso, por exemplo, das redes socais. Neste trabalho é apresentada a proposta e o desenvolvimento de uma arquitetura capaz de extrair características do perfil e do contexto educacional dos usuários, através da rede social Facebook e realizar recomendações de recursos educacionais de forma individualizada e personalizada que sejam condizentes com essas características. A solução proposta é apoiada por técnicas de extração de informações e ontologias para a extração, definição e enriquecimento das características e interesses dos usuários. As técnicas de Extração de Informação foram aplicadas aos textos associados às páginas curtidas e compartilhadas por usuários nas suas redes sociais para extrair informação estruturada que possa ser usada no processo de recomendação de recursos educacionais. Já as ontologias foram usadas para buscar interesses relacionados aos temas extraídos. A recomendação é baseada em repositório de objetos de aprendizagem e em repositórios de dados ligados e é realizada dentro das redes sociais, aproveitando o tempo despendido pelos usuários nas mesmas. A avaliação da proposta foi feita a partir do desenvolvimento de um protótipo, três provas de conceito e um estudo de caso. Os resultados da avaliação mostraram a viabilidade e uma aceitação relevante por parte dos usuários no sentido de extrair informações sobre os seus interesses educacionais, geradas automaticamente da rede social Facebook, enriquecê-las, encontrar interesses implícitos e usar essas informações para recomendar recursos educacionais. Foi verificada também a possibilidade da recomendação de pessoas, permitindo a formação de uma rede de interesses em torno de um determinado tema, indicando aos usuários bons parceiros para estudo e pesquisa. / There are several educational resources distributed in different repositories that address to a wide range of subjects and have different educational goals. The proper choice of these educational resources is a challenge for users who want to use them for their intellectual development. In this context, recommendation systems may help users in this task.In order to be able to generate personalized recommendations, it is important to identify information that will help to define user profile and assist in identifying his/her needs and interests. The constant and ever-increasing use of some technological tools allows the identification of different information about profile, interests, preferences, interaction style and user behavior from the spontaneous interaction that occurs in these systems, as, for example, the social networks. This paper presents the proposal and the development of one architecture able to extract users´ profile characteristics and educational context, from the Facebook social network and recommend educational resources in individualized and personalized manner, consistent with these characteristics. The proposed solution is supported by Information Extraction Techniques and ontologies for the extraction, enrichment and definition of user characteristics and interests. The Information Extraction techniques were applied to texts associated with “LIKE” and shared user´s pages on his social networks to extract structured information that can be used in the recommendation process of educational resources, the ontologies were used to search to interests related to extracted subjects. The recommendation process is based on learning objects repositories and linked data repositories and is carried out within social networks, taking advantage of user time spent at the web. The proposal evaluation was made from the development of a prototype, three proofs of concept and a case study. The evaluation results show the viability and relevant users´ acceptance in order to extract information about their educational interests, automatically generated from the Facebook social network, enrich these information, find implicit interests and use this information to recommend educational resources. It was also validated the possibility of people recommendation, enabling the establishment of interest network, based on a specific subject, showing good partners to study and research.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2015-12-10T12:29:28Z No. of bitstreams: 1 joaoguilhermecunhaevallo.pdf: 949071 bytes, checksum: b17b26c22e35d472ab0dc4057fa55bd9 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2015-12-10T14:10:44Z (GMT) No. of bitstreams: 1 joaoguilhermecunhaevallo.pdf: 949071 bytes, checksum: b17b26c22e35d472ab0dc4057fa55bd9 (MD5) / Made available in DSpace on 2015-12-10T14:10:44Z (GMT). No. of bitstreams: 1 joaoguilhermecunhaevallo.pdf: 949071 bytes, checksum: b17b26c22e35d472ab0dc4057fa55bd9 (MD5) Previous issue date: 2015-03-26 / O teletrabalho é uma das atividades mais relevantes para entender as dinâmicas de trabalho da contemporaneidade. Com o passar dos anos, aumentam os profissionais que, de alguma forma, dedicam parte ou a totalidade de suas jornadas a tarefas fora de um escritório fixo. Dependente da tecnologia e afim da inovação, a prática de trabalho a distância está sempre se atualizando. Trata-se de um campo fértil para os estudos de processos comunicacionais, seja pelo estudo das mídias em si, seja pela análise dos conteúdos ou quaisquer outro aspecto da comunicação humana que se intencione recortar. O fenômeno de comunicação que pretendemos investigar são as relações que os empregados estabelecem entre si e com a empresa em que trabalham quando estão em regime de teletrabalho. Mediadas por celulares e computadores, essas relações, acreditamos, definem o sucesso ou o insucesso das metas a serem alcançadas. Nossas hipóteses são atravessadas pela ideia de que a efetividade está ligada à adequação da comunicação entre os atores. A pesquisa começa pelas questões próprias dos estudos em redes sociais complexas. Em seguida, apresentaremos os modelos desenvolvidos para descrever esses fenômenos e optaremos por uma maneira de modelizar específica que trabalharemos melhor ao longo da dissertação. Concluiremos apresentando as mudanças apontadas pela teoria capazes de aprimorar os processos que nós modelamos e analisamos de forma crítica. / Telework is one most relevant activities to comprehend contemporary work dynamics. Over the years, more and more professionals have adopted homeoffice journeys, but also other formats of work away from the office. Dependent on technology and innovation, working upon distance is an always updating matter. This is surely a fertile ground for studies about communication processes, study of the media itself and content analysis or any other aspect of human communication. The communication phenomenon that we intended to investigate are the relations established by employees among themselves and directed to the company when teleworking. Mediated by telephones and computers, these relations, as we believe, are determinant to say if a process is successful or a failure. Our hypotheses are crossed by the idea that the effectiveness is linked to some level of harmony perceivable in communication between actors. The pursuit of our goal begins with the studies in complex social networks and technology development. Then we tried to sketch a simple model to understand the phenomena in regard to the methodology used, which will be described best along the lasts chapters of the dissertation. Finally, we conclude pointing some changes induced by the theory to enhance the processes we modeled and analyzed critically.

Online communities provide a fertile ground for analyzing people\'s behavior and improving our understanding of social processes. For instance, when modeling social interaction online, it is important to understand when people are reacting to each other. Also, since both people and communities change over time, we argue that analyses of online communities that take time into account will lead to deeper and more accurate results. In many cases, however, users behavior can be easily missed: users react to content in many more ways than observed by explicit indicators (such as likes on Facebook or replies on Twitter) and poorly aggregated temporal data might hide, misrepresent and even lead to wrong conclusions about how users are evolving. In order to address the problem of detecting non-explicit responses, we present a new approach that uses tf-idf similarity between a user\'s own tweets and recent tweets by people they follow. Based on a month\'s worth of posting data from 449 ego networks in Twitter, this method demonstrates that it is likely that at least 11% of reactions are not captured by the explicit reply and retweet mechanisms. Further, these uncaptured reactions are not evenly distributed between users: some users, who create replies and retweets without using the official interface mechanisms, are much more responsive to followees than they appear. This suggests that detecting non-explicit responses is an important consideration in mitigating biases and building more accurate models when using these markers to study social interaction and information diffusion. We also address the problem of users evolution in Reddit based on comment and submission data from 2007 to 2014. Even using one of the simplest temporal differences between usersyearly cohortswe find wide differences in people\'s behavior, including comment activity, effort, and survival. Furthermore, not accounting for time can lead us to misinterpret important phenomena. For instance, we observe that average comment length decreases over any fixed period of time, but comment length in each cohort of users steadily increases during the same period after an abrupt initial drop, an example of Simpson\'s Paradox. Dividing cohorts into sub-cohorts based on the survival time in the community provides further insights; in particular, longer-lived users start at a higher activity level and make more and shorter comments than those who leave earlier. These findings both give more insight into user evolution in Reddit in particular, and raise a number of interesting questions around studying online behavior going forward. / Comunidades online proporcionam um ambiente fértil para análise do comportamento de indivíduos e processos sociais. Por exemplo, ao modelarmos interações sociais online, é importante compreendemos quando indivíduos estão reagindo a outros indivíduos. Além disso, pessoas e comunidades mudam com o passar do tempo, e levar em consideração sua evolução temporal nos leva a resultados mais precisos. Entretanto, em muitos casos, o comportamento dos usuários pode ser perdido: suas reações ao conteúdo ao qual são expostos não são capturadas por indicadores explícitos (likes no Facebook, replies no Twitter). Agregações temporais de dados pouco criteriosas podem ocultar, enviesar ou até levar a conclusões equivocadas sobre como usuários evoluem. Apresentamos uma nova abordagem para o problema de detectar respostas não-explicitas que utiliza similaridade tf-idf entre tweets de um usuário e tweets recentes que este usuário recebeu de quem segue. Com base em dados de postagens de um mês para 449 redes egocêntricas do Twitter, este método evidencia que temos um volume de ao menos 11% de reações não capturadas pelos mecanismos explicitos de reply e retweet. Além disso, essas reações não capturadas não estão uniformemente distribuídas entre os usuários: alguns usuários que criam replies e retweets sem utilizar os mecanismos formais da interface são muito mais responsivos a quem eles seguem do que aparentam. Isso sugere que detectar respostas não-explicitas é importante para mitigar viéses e construir modelos mais precisos a fim de estudar interações sociais e difusão de informação. Abordamos o problema de evolução de usuários no Reddit com base em dados entre o período de 2007 a 2014. Utilizando métodos simples de diferenciação temporal dos usuários -- cohorts anuais -- encontramos amplas diferenças entre o comportamento, que incluem criação de comentários, métricas de esforço e sobrevivência. Desconsiderar a evolução temporal pode levar a equívocos a respeito de fenômenos importantes. Por exemplo, o tamanho médio dos comentários na rede decresce ao longo de qualquer intervalo de tempo, mas este tamanho é crescente em cada uma das cohorts de usuários no mesmo período, salvo de uma queda inicial. Esta é uma observação do Paradoxo de Simpson. Dividir as cohorts de usuários em sub-cohorts baseadas em anos de sobrevivência na rede nos fornece uma perspectiva melhor; usuários que sobrevivem por mais tempo apresentam um maior nível de atividade inicial, com comentários mais curtos do que aqueles que sobrevivem menos. Com isto, compreendemos melhor como usuários evoluem no Reddit e levantamos uma série de questões a respeito de futuros desdobramentos do estudo de comportamento online.

In this study social network analysis is used to empirically map out existing collaborative social networks influencing water governance in the Mkindo catchment, in Tanzania. I assess how existing social networks may affect the capacity to govern water and explore how knowledge about these networks can be used to facilitate more effective or adaptive water resources management. The study is the first of its kind to apply social network analysis to organizations influencing both blue water (the liquid water in rivers, lakes and aquifers) and green water (the soil moisture used by plants) at the catchment scale. Using a questionnaire and semi-structured interviews, social network data for 70 organizations was generated. With the help of social network analysis software1, the reciprocated collaborative interactions within the water governance network were traced, to better understand how the network facilitates and constrains individual actors, as well as the whole network, in managing water resources. Results show that there is currently no organization that coordinates the various land and water related activities at the catchment scale. Furthermore, there are important actors influencing water governance at the catchment scale, but they are not adequately integrated to the formal water governance system. Water user associations (WUA’s) are in the process of establishment, and could bring together actors presently not part of the formal governance system. However, at the moment the establishment of WUA’s seems to follow a top-down approach that fails to consider the existing informal organization of water users that are revealed through this social network approach. Instead of imposing institutional arrangements I argue that it is more promising and effective to identify and build on existing social structures. Social network analysis can help to identify existing social structures and points for interventions to increase the problem solving capacity of the governance network.

Sammanfattning Titel: ” Man kan inte springa ifrån ödet och inte annonserna ”- En kvalitativ fokusgruppsstudie i hur konsumenter uppfattar värdet av annonser på sociala medier Nivå: Examensarbete på Grundnivå (kandidatexamen) i ämnet företagsekonomi Författare: Bente Juel Handledare: Jonas Kågström Datum: 2019-september Syfte: Syftet med studien är att få en ökad förståelse för hur konsumenter uppfattar värdet av annonser på sociala medier utifrån ett antal nyckelfaktorer. Metod: I studien har kvalitativ arbetsmetod använts. Data har samlats in genom fokusgruppsintervjuer, analyserats genom transkribering, kodning och viktningsfaktorer och redovisats i löpande text med koppling till redan genomförd forskning. Respondenterna använder Facebook, är 50 år eller äldre och har olika kulturella bakgrunder. Resultat & slutsats: Det finns kulturella skillnader i konsumenters uppfattning av annonsvärde på sociala medier. Informationsvärde, underhållningsvärde, trovärdighetsvärde, interaktivitetsvärde, förköpsmotivation och social påverkan påverkar annonsvärdet positivt. Irritationsvärde påverkar negativt. Företag bör göra informativa, underhållande och trovärdiga annonser. Examensarbetets bidrag: Studien ger värdefulla insikter för marknadsförare och forskare i hur faktorerna undersökta i studien påverkar konsumenters uppfattningar av annonsvärde på sociala medier. Förståelsen för hur konsumenter uppfattar värdet av annonser på sociala medier och Facebook ökar. Studien ger företag insikter i hur de ska utforma sina annonser på sociala medier för att konsumenter ska uppfatta dem som värdefulla.   Förslag till vidare forskning: Vidare forskning bör, utgående från faktorerna i studien, undersöka hur olika åldrar och kön men samma kulturella bakgrund, påverkar hur konsumenter uppfattar annonsvärdet på sociala medier. Även studier av om det finns kulturella skillnader i påverkan av faktorerna i denna studie mellan respondenter av samma kön och ålder med olika kulturella bakgrunder är intressant i vidare forskning.   Nyckelord: ”consumer attitudes”, ”consumer value”, ”ads on Facebook”, ”social network advertising” och ”Facebook advertising”

Firms are interested in identifying customers who generate the highest revenues. Typically, customers are regarded as isolated individuals whose buying behavior depends solely on their own characteristics (e.g., previous purchase behavior, demographics etc.). In a social network setting, however, customer interactions can play an important role in purchase behavior. This thesis develops a generalizable methodology to identify high-value customers in a network. Previous work on social networks has focused most attention on modeling the interaction between individuals and understanding the positions of individuals in a network (e.g., measuring the influence of an individual based on his/her degree of network centrality). Little is known about how network influence directly translates into the benefits to the firm. In this study, the importance of taking into account both an individual characteristics and network effects when measuring customer value is argued. Drawing upon the spatial statistics literature, a spatial autocorrelation model is constructed that explicitly shows how these effects interact in generating firm revenue. This model is applied to a unique user-level dataset from a popular online gaming company in Korea. The data contain information about demographics of individual gamer, interaction between gamers, behavior within the game environment, and revenues generated by each individual. First, we propose a static model studying gamers' revenue in one period. We quantify the relative impact of an individual characteristics and network effects on revenue. The proposed static model shows better forecasts of an individual's value within a network for the firm than the benchmark models. The empirical analysis shows that individuals who are most influential in a network sense are not necessarily individuals who have the highest customer value. Next, we incorporate the spatio-temporal aspects of social influence in a network into the static model. This model is extended to construct the spatial dynamic model to forecast revenue in a social network. Second, we account for the homophily effects by separating the contemporaneous network effects out into the contemporaneous, temporal, and spatio-temporal effects. The proposed spatial dynamic model allows us to quantify an individual value in a network in a long-term perspective. The dynamic model is shown to outperform the static, and the other benchmark models in quantifying an individual value in revenue generation to the firm. Lastly, a dynamic coevolution model to account for homophily is suggested and discussed for future research.

My dissertation challenges the dominant situational theory developed by Deutsch (1949) that conceptualizes cooperation and competition as situational factors equally shape all team members’ behaviors. Based on interdependence theory and social network techniques, I offer a configural theory that accounts for the complex, nonlinear patterns of within team cooperation and competition. Acknowledging the tension between team setting and conventional competition, I argue that within team competition is a restrained form of competition as its participants are bonded together by the team membership. Instead of competing for limited prizes or ranks that place individuals against each other, in typical team settings, team members compete for within team status. It has three dimensions, including demonstrating superiority over each team member on competence, participation and connection. I also argue that within team cooperation has three dimensions – sharing, helping and voicing that are directed towards each team member. I developed and validated social network-based measures of within team cooperation and competition based on a student sample in Study 1. The theoretical factor structure was supported. I then tested the overall research model in a field sample in Study 2. Utilizing quadratic assignment procedures, I found that characteristics of each dyad, including dependence, similarity and liking, are able to influence the cooperative behaviors within the dyad. However, why within team competition is differentiated was less consistent with what I expected. The overall pattern of within team cooperation and competition, captured by three network indices, density (i.e., overall connectedness), centralization (i.e., tie distribution), and subgrouping (i.e., disconnection), did not predict team performance. Future research directions are discussed.

How are arms export choices made within a state? In this dissertation I use a foreign policy analysis framework to examine this question. I focus on examining each of the three primary levels of analysis in international relations as it relates to the main question. I begin with a typical international relations level and examine the characteristics of the two states that dominate the world arms trade: The United States and Russia. I then examine the full network of relations among all states in the international system that are involved in the sale or purchase of arms. To do this I use an Exponential Random Graph Model (ERGM) to examine these relations, which I derived from data on arms sales from the Stockholm International Peace Research Institute (SIPRI). I examine the arms sales in each decade from 1950 through 2010. In order to answer the question of how arms decisions are made within the state, I focus my inquiry on the United States and Russia. It is these states that have the practical capability to use arms transfers as a foreign policy tool. I examine the foreign policy making mechanisms in each of these states to determine how arms transfers can be used as a foreign policy tool. I examine and the bureaucratic institutions within each state and come up with a state ordering preference for how arms decisions are evaluated in each state. Finally, I use case studies to examine arms relations between the both the U.S. and Russia and three other states in each case. The other states were selected based on the pattern of sales between the two countries. I examine these sales to determine the impact of bureaucratic maneuvering and interest politics on the decision-making process within Russia and the United States. I find in my network analysis that the traditional measures of state power - military spending, regime type, and military alliances - do not account for the overall structure of the arms sale network. The most important factors in the formation of the arms sale network in each of the six decades that I study are specific configurations of triadic relations that suggest a continued hierarchy in the arms sale network. I find in my case study chapters that a simple model of state interest as a decision-making rule accounts for the decisions made by the different bureaucratic actors in the U.S. Russian arms sales are driven by a state imperative to increase Russia's market share, and there is high-level involvement in making different arms deals with other countries.

While there is a growing trend to use social media for public health promotion, research on its actual potential to influence health behaviors is limited. This dissertation explores whether and how social network sites (SNSs) can be used to promote physical activity (PA) through electronic word of mouth (eWOM). Composed of two studies, this dissertation explores PA-related eWOM from both the senders' and receivers' perspectives, and examines actual messages. The first study uses a web survey and explores the antecedents and communication consequences of eWOM about leisure-time PA (LTPA), and the behavioral consequences of eWOM among college students. The second study is based on a content analysis of public Twitter posts in the U.S. in 2011 regarding PA. Based on Sun et al.'s (2006) Path Model of Antecedents and Consequences of Online Word of Mouth, it was found that undergraduate SNS users with higher affective involvement and stronger social ties with their SNS contacts were more likely to provide opinions or information about PA. People with stronger social ties were also more likely to seek opinions or information. Both opinion leadership and opinion seeking were associated with forwarding and chatting. Applying the Theory of Planned Behavior, the first study also found social support of PA via eWOM on SNSs is associated with both affective and instrumental attitudes, subjective norms, and perceived behavioral control (PBC), while social negativity of PA via eWOM on SNSs is associated with instrumental attitudes and PBC. Affective attitude, instrumental attitude, and PBC, in turn, predict intention to participate in LTPA. Moreover, when putting all these different constructs together to predict intention, social support via eWOM was found to indirectly influence the intention to participate in LTPA through the constructs in the Theory of Planned Behavior (including affective and instrumental attitudes and perceived behavioral control). Applying the components of both the Path Model of Antecedents and Consequences of Online Word of Mouth and the Social Cognitive Theory, the second study examined Twitter posts of PA-related eWOM. PA modeling dominated the different aspects of social influence. Most people chat rather than forward information, and provide rather than seek opinions and information about PA. PA type is associated with PA modeling in multiple ways. People with more followers are more likely to forward information about PA. This dissertation widens and deepens the understanding of PA-related eWOM on SNSs by the application of theoretical frameworks from both marketing and health behavior fields. The results suggest that people who find PA interesting and fun, perceive themselves as close to their contacts on SNSs, and have larger social network on SNSs can be recruited as opinion leaders in future interventions to promote PA. These opinion leaders can provide PA modeling and social support though SNSs which will increase their contacts' positive attitudes and PBC and consequently increase their intention to participate in PA.