We propose a novel network-based approach for location estimation in social media that integrates evidence of the social tie strength between users for improved location estimation. Concretely, we propose a location estimator – FriendlyLocation– that leverages the relationship between the strength of the tie between a pair of users, and the distance between the pair. Based on an examination of over 100 million geo-encoded tweets and 73 million Twitter user profiles, we identify several factors such as the number of followers and how the users interact that can strongly reveal the distance between a pair of users. We use these factors to train a decision tree to distinguish between pairs of users who are likely to live nearby and pairs of users who are likely to live in different areas. We use the results of this decision tree as the input to a maximum likelihood estimator to predict a user’s location. We find that this proposed method significantly improves the results of location estimation relative to a state-of-the-art technique. Our system reduces the average error distance for 80% of Twitter users from 40 miles to 21 miles using only information from the user’s friends and friends-of-friends, which has great significance for augmenting traditional social media and enriching location-based services with more refined and accurate location estimates.

Anyone can upload news instantaneously to Twitter in 140-characters or less, therefore it is important to assess the credibility of tweets, particularly during a foodborne illness outbreak. According to a Microsoft study there are numerous Twitter features that impact the credibility of tweets. This study examines students’ use of Twitter, and their perceptions of how features and sources impact the credibility of tweets related to a foodborne illness. An online survey was completed by Texas A&M University students classified as U3 juniors (N = 200) in social science-based majors in the College of Agriculture and Life Sciences. The study revealed students to be moderate users of Twitter. Eight features were identified to impact credibility: verified author topic expertise, account has verification seal, tweet contains grammar/punctuation mistakes, author is someone you’ve heard of, author is often mentioned/retweeted, author often tweets on topic, and author has many followers. Three Twitter identities a professor, student, and student organization, were created to measure tweet credibility. Tweets from the professor were perceived more credible than tweets attributed to student or student organization. The results indicated statistical differences between features attributed to each source. These findings can help sources determine what features can make tweets the most credible. This study has important implications for organizations that engage consumers on Twitter when breaking news such as a foodborne illness outbreak occurs.

Distributed online discussion events in social media are increasingly used as sites for open, informal professional development, knowledge sharing and community formation. Synchronous chat events hosted on Twitter have become particularly prominent in a number of professional domains. Yet theoretical and critical analysis of these Twitter chat events has, to date, been limited: this thesis contributes to the development of such analysis through a socio-material, network assemblage lens employing trans-disciplinary and multi-method research approaches. This research positions the Twitter chat events as the relational effects of network-assemblages of human and non-human actants. This thesis explores Twitter chat events with a particular focus on human resource development (HRD) as a professional domain that is widely seen as inherently changeable, fluid, contested and continually emergent. This study examines how practitioner-generated reportage of professional practice interact with the specific functions of Twitter to generate definitions of HRD as a professional field of practice. A combination of descriptive statistics, Social Network Analysis and analysis of the content and structure of the Chat events has been employed in researching 32 separate chat events with 12,061 tweets. The research methods generated multiple readings of the research data and surfaced different and fluid potential lines of enquiry in to the Twitter chat events. A number of these potential lines of enquiry were then selected as points of entry to ‘zoom in’ to the data using a Critical Discourse Analysis for a smaller sample of the chat events. The assemblages of the chat events are collective achievements involving human and non-human actants. The collective effects surfaced in the research problematise (a) the notion of online communities as the product of network ties and (b) the humanist orientations of much of the literature on professional learning. Within the Twitter chat events, HRD is constructed as a profession in crisis as the traditional bases of professional identity are eroded. The practitioners participating in these events position HRD as increasingly less relevant to its constituent audiences, clients and customers and as locked into organisational assemblages that cut-off the potential for new trajectories for the field to emerge. The chat events normalise technological and societal imperatives that create work intensification, demand committed lifelong learners and venerate precarious relations of employment. Hence, the domain of HRD is enacted as subservient to a new-capitalist discourse that emphasises adaptability, innovation and speed. A key finding of the research is that, in response to these challenges, the Twitter chat events seek to generate an idealised archetype of HRD bounded by a stable set of dominant practices. These practices emphasise the importance of self-directed learning, autonomous working and the capacities to cope with continuous change. Learning and development is positioned as the responsibility of the individual to enhance their employability within increasingly competitive labour markets. Thus, the idealised archetype of HRD is aligned with conceptualisations of a global post-industrial capitalism and with a notion of ‘enterprising selfhood’.

Ingeniero Civil Industrial / Los delitos en cualquier sociedad son una problemática que se intenta disminuir lo mayor posible. En Chile el robo de vehículos presenta tasas bastante elevadas, redondeando los 30.000 al año, lo que significa que un vehículo es sustraído cada 17 minutos en Chile. Esta investigación se enmarca en el proyecto de análisis de robos de vehículos desarrollado por PROSE, consultora que ofrece servicios de análisis y desarrollo a las empresas de seguros de vehículos de Chile, en conjunto con la Universidad de Chile y con el apoyo del Fondo de Fomento al Desarrollo Científico y Tecnológico. El proyecto pretende ayudar a entender y desarrollar un modelo predictivo del robo de vehículos utilizando 3 fuentes de información, denuncias de vehículos, medios noticiosos y Twitter. Twitter es una red social donde se comparten opiniones o declaraciones en tiempo real, los cuales son llamados Tweets, sus características han captado la atención de distintos investigadores que deciden utilizar esta información para explicar fenómenos sociales. Se han presentado problemas de interpretación de patrones o rendimiento de modelamientos predictivos al utilizar Twitter debido a sesgos inmersos en la red social, producidos por las características de los usuarios, como de localización, edad, contenido compartido o intereses. Es por esto que el objetivo principal de esta tesis es identificar las relaciones existentes entre el robo de vehículos y denuncias realizadas a través de Twitter en el periodo 2012 al 2016 con el fin de establecer las diferencias y similitudes entre ambas fuentes de datos. Para el desarrollo de esta tesis se consideran dos fuentes de datos, las denuncias de robos de vehículos almacenados por PROSE y denuncias realizadas por Twitter en el periodo 2012 al 2016. Se analizó la correlación de las denuncias entre ambas fuentes de datos, identificando que tienen una correlación de 0,73. Se recreó el proceso por los cuales pasa un robo de vehículo, en donde se descubrió que el orden es 1° Robo del vehículo, 2°Envío del Tweet, 3°.Denuncia en Carabineros de Chile, 4°Validación PROSE, y finalmente el Hallazgo. Es decir el Tweet es el primer evento que se origina luego del robo. Además se descubrió que aquellos vehículos que son denunciados por twitter presentan tasas de hallazgo superiores, conocimiento valioso para futuros trabajos. Algunos de los sesgos encontrados fueron que en Twitter se denuncia en una mayor proporción los vehículos de menor valor, además de mostrar que los modelos denunciados tienen tasas de frecuencias similares en ambas fuentes de información.

abstract: Online social networks, including Twitter, have expanded in both scale and diversity of content, which has created significant challenges to the average user. These challenges include finding relevant information on a topic and building social ties with like-minded individuals. The fundamental question addressed by this thesis is if an individual can leverage social network to search for information that is relevant to him or her. We propose to answer this question by developing computational algorithms that analyze a user's social network. The features of the social network we analyze include the network topology and member communications of a specific user's social network. Determining the "social value" of one's contacts is a valuable outcome of this research. The algorithms we developed were tested on Twitter, which is an extremely popular social network. Twitter was chosen due to its popularity and a majority of the communications artifacts on Twitter is publically available. In this work, the social network of a user refers to the "following relationship" social network. Our algorithm is not specific to Twitter, and is applicable to other social networks, where the network topology and communications are accessible. My approaches are as follows. For a user interested in using the system, I first determine the immediate social network of the user as well as the social contacts for each person in this network. Afterwards, I establish and extend the social network for each user. For each member of the social network, their tweet data are analyzed and represented by using a word distribution. To accomplish this, I use WordNet, a popular lexical database, to determine semantic similarity between two words. My mechanism of search combines both communication distance between two users and social relationships to determine the search results. Additionally, I developed a search interface, where a user can interactively query the system. I conducted preliminary user study to evaluate the quality and utility of my method and system against several baseline methods, including the default Twitter search. The experimental results from the user study indicate that my method is able to find relevant people and identify valuable contacts in one's social circle based on the query. The proposed system outperforms baseline methods in terms of standard information retrieval metrics. / Dissertation/Thesis / M.S. Computer Science 2010

Tesis para optar al grado de Magíster en Marketing / Autor no envía autorización para el acceso a texto completo de su documento / El presente estudio analiza la relación que existe entre las motivaciones psicológicas y la confianza con la actitud hacia el uso de Twitter en Chile. Considerando entre las motivaciones, el entretenimiento, la sociabilidad y la información. Adicionalmente a esto se analiza el uso que se le da a la plataforma en términos de tiempo promedio diario, las actividades que se llevan a cabo, las categorías revisadas y las acciones, entendiéndose como acciones leer, publicar o las dos. Este estudio es cuantitativo de tipo concluyente, el instrumento fue aplicado a 270 estudiantes universitarios de pregrado y postgrado de Universidades de Santiago de Chile, por medio de la página web Qualtrics.com y físicamente. Una vez procesadas las respuestas, se hizo un análisis de fiabilidad y factorial para medir la validez de la escala, posteriormente se realizó un modelo estructural para ver la relación entre las variables independientes y la dependiente mediante “Structural Equation Model” (SEM). Esto arrojo como resultado que había un efecto significativo entre las motivaciones entretenimiento y sociabilidad sobre la actitud, al igual que de la confianza sobre la actitud, la motivación información no tuvo un efecto significativo sobre la variable actitud por lo que se rechazó esa hipótesis al finalizar el estudio. A su vez, la variable actitud tuvo un efecto significativo sobre el uso.

ADHD is the most commonly diagnosed neurobehavioral disorder among children. While ADHD in Western countries has long been recognized and increasingly diagnosed in recent years, there is a growing recognition of this disorder as a significant cross-cultural phenomenon. Saudi studies to date vary in their estimation of prevalence of ADHD, with overall prevalence estimated to be between 3.5% and 6.5%, while the worldwide prevalence of ADHD is 5.29%.This study is a thesis by three articles. The first article examines the representations of ADHD by the Saudi ADHD Society members on Twitter because, as the only charity serving people with ADHD in Saudi Arabia, they have come to define how ADHD is talked about there. The Society’s Twitter account (@adhdarabia) has over 13,500 followers. Tweets posted between December 1st, 2016 and January 31st, 2017 were collected, with those announcing events and retweets from other accounts eliminated. This resulted in 141 tweets discussing the nature, causation, and treatment of ADHD. The content of these tweets was analyzed using Foucauldian discourse analysis. Findings reveal that the Society’s Twitter account shows members constructing ADHD as an experience of suffering; their comments position children with ADHD as sufferers, often subject to additional problems. An alternative discursive construction of ADHD is that caring for a child with ADHD is a ‘different’ kind of responsibility for parents and teachers, who must be advised by ‘experts’. The implications of these discourses are discussed in this paper.The second article uncovers the lived experience of parents with a child who has had an ADHD diagnosis in Saudi Arabia, and examines how their experiences can be understood in relation to the multiple and competing discourses of ADHD that frame their daily lives. Which discourses do parents draw upon – and reinforce – as they describe their experiences of ADHD, and which discourses do they resist? This study carried out in-depth interviews with seven Saudi parents who have at least one child diagnosed with ADHD, or any of its subtypes, between the ages of two and 11. Foucauldian discourse analysis (FDA) is applied in analyzing parental ADHD discourses, uncovering how these parents made sense of ADHD pre- and post-diagnosis. Four main discourses emerged in the process: ADHD as normal behavior (pre-diagnosis), and ADHD as emerging from supernatural/religious, medical, and social environment contexts (post-diagnosis). This paper also emphasises that the causes of ADHD must be considered in the wider context of misconceptions and uncertainty among Saudi parents. All the participants in this research were influenced by a combination of discourses in their attempts to make sense of their children’s symptoms.The third article explores the discourses drawn upon, reinforced and resisted by six Saudi teachers and four clinicians as they describe their experiences and understanding of ADHD. Saudi clinicians approach ADHD as an extension of American medical views in terms of its causes, diagnosis and treatment. Alarmingly, in light of the shortage of recommended ADHD medications, there are accounts of antipsychotic medications being prescribed for children. Saudi teachers’ views of ADHD were an extension of the medical discourse; this meant that students’ strengths were ignored and the focus was entirely on negative behavioral patterns. Despite a tendency to attribute ADHD to genetics, teachers objectified students who ‘acted out’ as having ADHD or even other disorders (when the child’s behavior or symptoms diverged from their limited understanding of ADHD). Parents who do not comply with teachers’ suggestions are blamed for any lack of improvement in the child’s behavior or academic attainment. Teachers’ accounts also revealed some serious pressures on them as a result of large class sizes and a lack of training in how to teach and manage students with ADHD. These findings have implications for individuals and institutions providing ADHD education to both doctors and teachers, and reinforce calls for researchers to examine ADHD outside of the genetic ‘box’.

Submitted by Pós-Com Pós-Com (pos-com@ufba.br) on 2013-09-05T15:44:33Z No. of bitstreams: 1 Nina Fernandes dos Santos.pdf: 3945252 bytes, checksum: 153321850b464707b60fd65f05e7c028 (MD5) / Approved for entry into archive by Rodrigo Meirelles(rodrigomei@ufba.br) on 2013-09-09T17:40:57Z (GMT) No. of bitstreams: 1 Nina Fernandes dos Santos.pdf: 3945252 bytes, checksum: 153321850b464707b60fd65f05e7c028 (MD5) / Made available in DSpace on 2013-09-09T17:40:57Z (GMT). No. of bitstreams: 1 Nina Fernandes dos Santos.pdf: 3945252 bytes, checksum: 153321850b464707b60fd65f05e7c028 (MD5) Previous issue date: 2012 / CNPQ - Conselho Nacional de Desenvolvimento Científico e Tecnológico. / Partindo do conceito de visibilidade e de sua importância para a dinâmica política, essa dissertação busca compreender os processos de disseminação e ganho de visibilidade de temas nos sites de rede sociais. As consequências políticas desses processos de visibilidade são igualmente objeto de estudo aqui, a partir da compreensão da importância política da esfera de visibilidade pública. Para tanto, utilizam-se como estudo de caso os discursos que circularam no Twitter sobre três temas: o aborto de anencéfalos, a lei da Ficha Limpa e as cotas nas universidades. Através da análise da rede de usuários formada ao redor dos temas, suas conexões e padrões de replicação e conversação, consegue-se caracterizar como se dá o processo de disseminação do conteúdo na rede e analisar seu impacto político. Os resultados mostram que os padrões de difusão de informações no Twitter diferirem muito do padrão de radiodifusão dos meios de comunicação tradicionais. A influência de atores sociais que já detêm grande visibilidade – como os próprios meios de comunicação -, no entanto, é alta nessa rede, sendo responsável por alguns dos clusters de disseminação de informação. / Programa de Pós-Graduação em Comunicação e Cultura Contemporâneas

Submitted by Pós-Com Pós-Com (pos-com@ufba.br) on 2015-01-16T13:19:33Z No. of bitstreams: 1 Nadia Moragas.pdf: 1179254 bytes, checksum: 59d5dcfe0cba4e2687361a6ebc18ccf6 (MD5) / Approved for entry into archive by Vania Magalhaes (magal@ufba.br) on 2018-01-23T13:56:47Z (GMT) No. of bitstreams: 1 Nadia Moragas.pdf: 1179254 bytes, checksum: 59d5dcfe0cba4e2687361a6ebc18ccf6 (MD5) / Made available in DSpace on 2018-01-23T13:56:47Z (GMT). No. of bitstreams: 1 Nadia Moragas.pdf: 1179254 bytes, checksum: 59d5dcfe0cba4e2687361a6ebc18ccf6 (MD5) / Capes / Nossa pesquisa insere-se no campo de problematizações da prática jornalística em Redes Sociais, especificamente no formato microblog, através do Twitter. Objetivamos identificar as permanências e alterações presentes no texto jornalístico do Twitter em relação à lógica discursiva do jornalismo tradicional. Para tanto, foram analisados 3184 tweets publicados por organizações jornalísticas consideradas de referência na área (El País e The Guardian) através de contas de três editoriais (breaking news, política e cultura) no microblog. A pesquisa conta com um breve levantamento do jornalismo, sua origem e principais paradigmas, bem como com uma recuperação do conceito de narrativa e das técnicas de redação empregadas no jornalismo padrão. Este estudo também traz revisão bibliográfica dos estudos acerca das Redes Sociais, assim como do formato microblog e da apropriação jornalística do Twitter. Nosso pressuposto é a emergência de um texto jornalístico característico do jornalismo praticado em microblog com a apropriação de elementos de linguagem suscitados pela ferramenta. Entretanto, consideramos que este texto jornalístico, apesar de contar com novos elementos, não difere-se muito da lógica discursiva tradicional por apresentar estrutura apoiada no modelo de pirâmide invertida, com hierarquização por critérios de relevância, linguagem padrão condizente com a empregada no webjornalismo, critérios de noticiabilidade e valores/notícia equivalentes ao jornalismo, independentemente de sua manifestação. / Our research falls within the field of journalism practice in Social Networks, specifically about microblogging through Twitter. We aimed to identify the continuities and changes in the journalistic text of Twitter regarding the discursive structure of traditional journalism. Therefore, we ana lyzed 3184 tweets posted by reference news organizations (El País and The Guardian) , through accounts of three editorials (breaking news, politics and culture) in the microblog. The research includes a brief reflection about journalism, its origin and main paradigms, as well as a recovery of the concept of narrative and writing techniques employed standard in journalism. This study also brings literature review of studies on the social networks, as well as the format of microblog and its journalistic appropriation by Twitter. Our assumption is the emergence of a journalistic text characteristic of journalism practiced in microblog with the appropriation of language elements raised by the tool. However, we consider that this journalistic text, despite having new elements, does not differ greatly from the discursive logic by presenting traditional structure based on the model of an inverted pyramid, with ranking by relevance criteria, consistent with the standard language used in web journalism, criteria values of newsworthiness and news journalism equivalent regardless of its manifestation.

Made available in DSpace on 2016-02-12T01:05:04Z (GMT). No. of bitstreams: 1 000477185-Texto+Completo-0.pdf: 14059108 bytes, checksum: 4b4b7aea8238502c84d93affb300de2a (MD5) Previous issue date: 2015 / The location-based services (SBL) represent the combination of mobile communication technologies, internet and geographic information systems. This triad has modified the relationship with people, with physical places and cyberspace. Journalism has also been impacted in regard to content production and consumption, and some initiatives already seek to take advantage of the potentialities inherent to the SBL, such as the better understanding of the context of facts and users and the possibility of offering targeted content. Among the concepts and authors studied stand out: the space concepts (Certeau and Heidegger), cyberspace (Lemos and Santaella), online journalism (Canavilhas and Palácios) and geolocation (Brimicombe and Li), examined under the definitions offered by the Medium Theory (Innis, McLuhan and Meyrowitz), aiming to understand their background and history to the present day and, based on case studies, to verify what is being done in journalism based on location at the present time and to examine their current and future potential. / Os serviços baseados em localização (SBL) representam a associação de tecnologias de comunicação móvel, internet e sistemas de informação geográfica. Essa tríade tem modificado as relações com as pessoas, com os lugares físicos e com o ciberespaço. O jornalismo também vem sendo impactado no que se refere à produção de conteúdo e ao consumo, sendo que algumas iniciativas já procuram tirar proveito das potencialidades inerentes aos SBL, como uma melhor compreensão do contexto dos fatos e dos usuários e a possibilidade de oferta segmentada de conteúdo. Entre os conceitos e autores estudados destacam-se: os conceitos de espaço (Certeau e Heidegger), ciberespaço (Lemos e Santaella), ciberjornalismo (Canavilhas e Palácios) e geolocalização (Brimicombe e Li), analisados sob o viés da Teoria do Meio (Innis, Mcluhan e Meyrowitz), visando compreender sua formação e história até a atualidade e, com base em estudos de caso, verificar o que é feito no jornalismo baseado em localização no presente momento, assim como a analisar suas potencialidades atuais e futuras.