Information Diffusion and Social Influence in Online Networks.

The explosive growth of online social systems has changed how individuals consume and disseminate information. In this thesis, we conduct large-scale observational and experimental studies that allow us to determine the role that social networks play in information diffusion online, and the factors that mediate this influence. We first examine the adoption of user-created content in a virtual world, and find that social transmission appears to play a prominent role in the adoption of content. Ultimately, we are faced with a critical problem that underlies all contemporary empirical research on social influence: how do we measure whether individuals in a network influence one another, when the basis for their interaction rests upon commonalities that are predictive of their future behavior? We use two coupled experiments to address this question. In our first experiment, we randomize exposure to social signals about friends' information sharing behavior to determine the causal effect of networks on diffusion among 253 million subjects in situ. Our second experiment further tests how social information affects individual sharing decisions when viewing content. Finally, this thesis concludes with a study that examines how individuals allocate attention across their network of contacts, which has implications for influence and information diversity in networks.Ph.D.InformationUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/89838/1/ebakshy_1.pd

Social Media Use: A Critical Analysis of Facebook\u27s Impact on Collegiate EFL Students\u27 English Writing in Thailand

In this technology era, a new trend of using Social Media or Social Networking Sites (SNSs) has been recently highlighted. Social media influences people’s lives in many aspects including education and English language learning. The purpose of this study is to examine whether using Facebook online impacts the type (formal or informal) of English EFL students use for in-class writing or not, as well as to understand the students’ perceptions on how the use of Facebook helps to facilitate or inhibit their English writing skills. The study was conducted by using qualitative research methods to explore EFL college students’ writing behavior on the Facebook platform and understand the perspectives of students involved in using Facebook. The data collection methods were observation and interviews. Participants consisted of 32 students, mostly freshmen college students. The site for this study was Center Bangkok University (CBU, pseudonym) in Thailand, a university located in Bangkok. The study took place during a 5-week period from November 11, 2013 until December 12, 2013. The interviews were conducted with 16 students from the 32 and two teachers, each lasting about 45-60 minutes. After the data was coded and analyzed, three major findings that answer the research questions were emerged

The impact of using social networking sites on academic relations and student learning in University setting

This study investigates academic relations of educators, tutors, and students in university settings. Academic relations refer to the controlling and productive relations of power that operate at both societal and interpersonal level between academic actors and through them, knowledge is produced and identities are constructed. From a Critical theoretical point of view, power is unequally distributed in society and psychological development is fundamentally mediated by power relations which are socially and historically constituted. Given the capacity of power configurations to influence learning coupled with the fact that such relations are both relational and psychological, the notion of unequal social power is critical to understanding academic relations in university settings. The psychological and relational aspects of power suggest that underprepared students from disadvantaged academic backgrounds may suffer a sense of powerlessness and social domination as they interact with academics and more capable peers from privileged academic backgrounds. Research suggests that students (especially the previously disadvantaged) form peer-based knowledge sharing clusters (for example, study groups) to augment their intellectual potential and resource limitations. Mindful of these underprepared students' social domination (social and psychological) by high achieving peers and academics, and the capacity of peer-based clusters/ relations to democratise academic relations through presenting opportunities for exchange of perspectives, these peer-based relations present viable proxies for unpacking academic relations. The problem, therefore, is that while academic relations (lecturer-student, tutor-student, and student-peer) in face-to-face contact are quite central to student meaningful learning and transformation, capturing and studying these relations is complex. This complexity is explicated by the incapacity of traditional classrooms to capture and sustain academic relations due to: 1) The temporality, time and spatially bounded nature of academic relations in class, 2) Class sizes, academics' huge workloads and time constraints that limit one-on-one lecturer-student engagements especially at undergraduate level 3) Transmission pedagogy and classroom space configuration that mute lateral discourses, and 4) Student complex histories and cultural diversity. Research suggests that student knowledge sharing clusters are shifting from face-to-face to social networking sites (SNS), that is, online social networks that support group collaboration vii and support. The persistence of these online interactions, opportunities for peer-based discourses, peer-generation of artefacts on SNS challenge the limitations of traditional classrooms, making SNS essential for unpacking classroom lecturer-student and student-peer relations by proxy (if academics participate). These opportunities, and computer-mediated communication theory' suggestion that computer-mediated nature of textual interaction has potential to undermine status, gender and power asymmetries built in face-to-face interaction inform my thesis that SNS interaction has potential to equalise power relations of academic actors. The goal of this study was therefore, to use lecturer-student, student-peer interaction on SNS as proxies for unpacking academic relations and learning that unfold in traditional academic settings (classrooms, computer laboratories). The research question instigated the impact of lecturer-student, student-peer interaction on the academic /power relations and learning of academics and students in formal university settings. Using a Critical ethnographic approach, the research investigated power relations and learning manifested in: 1. academics and student text-based messages posted on SNS (Facebook), 2. lecturer and student experiences of using Facebook and its influence on classroom interactions, and 3. Lecturer-student and student peer interactions in class. Mindful of the democratisation potential of computer-mediated communication (CMC) on previously disadvantaged learners, the relational nature of power, the influence of structural forces on mediated interaction and higher mental development, this research was informed by three theories namely, Critical Theory of Technology (CTT), Critical Theories of Power (CTP), and Cultural Historical Activity Theory (CHAT), respectively. As a participant observer in online ethnography, the researcher employed CTT to examine the democratisation potential and constraints of computer-mediated communication (that is SNS) on learning and academic relations. While CTT was useful for examining the technological effects on mediated learning, the theory was less insightful for unpacking the power contestations in text-mediated discourses. To this end, Critical Discourse Analysis' (CDA) (which draws on CTP) was employed to examine how vertical and horizontal relational power were articulated and contested via textual messages, to complement CTT in its limitations. Although CTP was insightful for the examination of power manifested in lecturer-student, and peer-based interaction, CTP equally proved inadequate for the examination of mediated learning, that is, the role of artefact-mediated action on psychological development. Mindful viii of CHAT's focus on the influence of symbolic mediation on psychological development, CHAT offered a rational complement to CTP for the examination of mediated learning. This was important given that this research on academic/power relations and student learning unfolded in a technology-mediated learning environment (that is SNS). CHAT was adopted as a theoretical and methodological approach to examine how mediated interaction and the interplay of different elements of the lecture activity system impacted on student psychological development and lecturer's teaching practices. In summary, the study examined these empirical materials: text-based interactions (lecturer and student Facebook postings), lecturer and student narratives of lectures and Facebook interactions (interview transcripts, lecturer debriefings after classroom observations), in-class actions and discourses (lecture observations and focus group discussions). The findings of this study are that SNS democratized academic relations and communication for academically inclined students through: widening the academic networking space, breaching lecturer-student social boundaries that often hindered student access to knowledge resources, and offering 'safe haven' for student contestation of unpopular academic practices. Facebook also allowed shy and timid students to be more assertive in requesting academic support. The unintended effect of SNS was that it reconfigured peer-based relations as high achievers assumed additional vertical, 'super tutor' roles of advising peers. Facebook also regulated in-class interaction by hiving off mundane questions on course administration and practicals from the class. SNS thus augmented classroom interaction as online and classroom learning cross fertilised each other. The practical contribution of this work is in the insight into how student informal academic and social support online networks could be drawn upon in student in-class learning. The study proposed a 'best practice' pedagogical model/ strategy that draws on: 1) Informal peer-based and lecturer-student knowledge sharing on Facebook and associated SN tools, 2). Student reflexivity on self-generated and peer-generated content, and 3). Self and peer-based evaluation as a basis for academic empowerment. The theoretical contribution lies in the methodology or approach for analysing the interplay between academic relations and student learning using SNS as proxy. In particular, this work contributes a new body of knowledge through the integration of Critical Theories (Critical Theories of Power and Critical Theories of Technology) and CHAT

Unsupervised learning of latent edge types from multi-relational data

Many relational datasets, including relational databases, feature links of different types (e.g., actors act in movies, users rate movies), known as multi-relational, heterogeneous, or multilayer networks. Edge types/network layers are often not explicitly labeled, even when they influence the underlying graph generation process. For example, IMDb lists Tom Cruise as a cast member of Mission Impossible, but not as its star. Inferring latent layers is useful for relational prediction tasks (e.g., predict Tom Cruise’s salary or his presence in other movies). This thesis discusses Latent Layer Generative Framework - LLGF, a generative framework for learning latent layers that generalizes Variational Graph Auto-Encoders (VGAEs) with arbitrary node representation encoders and link generation decoders. The decoder treats the observed edge type signal as a linear combination of latent layer decoders. The encoder infers parallel node representations, one for each latent layer. We evaluate our proposed framework, LLGF, on eight benchmark graph learning datasets for this study. Four of the datasets are heterogeneous (originally labeled with edge types); we apply LLGF after removing the edge labels to assess how well it recovers ground-truth layers. LLGF increases link prediction accuracy, especially for heterogeneous datasets (up to 5% AUC), and recovers the ground-truth layers exceptionally well

Do they all act the same? : identification of the strategies associated with different types of online sex solicitors' discourses

L’avancement des technologies a permis aux agresseurs sexuels de mineurs d’avoir de nouvelles opportunités de commettre des infractions à caractère sexuel en ligne (Fortin, Paquette, & Dupont, 2018; Seto, Hanson, & Babchishin, 2011). Avec un nombre de plaintes criminelles croissant (Wolak, Finkelhor, & Mitchell, 2012), le phénomène du leurre informatique pose de nombreux défis pour les enquêteurs qui doivent développer des méthodes d'enquête pour distinguer les dossiers ayant le plus de risque de passage à l’acte afin d’assurer la protection du public. Le projet de recherche vise à distinguer les différents types de cyber-relations basées sur les stratégies utilisées dans les discours d’auteurs de leurre. En analysant les différences entre les auteurs de leurre qui ne demande pas un contact hors ligne, ceux qui n’ont pas été capables d’obtenir un contact et ceux qui ont obtenu un contact hors ligne, on vise à identifier les stratégies associées aux discoures des interactions menant aux contacts hors ligne. L’étude utilise une combinaison d’approche qualitative et quantitative. L’analyse des conversations en ligne a été faite à partir de données policières de la Surêté du Québec . La transformation des données qualitatives en quantitative a été fait pour conduire les analyses statistiques. Les résultats suggèrent que les stratégies associées aux interactions qui ont mené au passage hors ligne sont : la persistance, la pratique en ligne des fantaisies sexuelles et d’avoir des opportunités à risque limité de détection d’une figure faisant autorité. Les auteurs de leurre avec contact ont utilisé ces stratégies de manière plus récurrente que les auteurs de leurre sans contact. En outre, les victimes qui participent plus et qui résistent le plus ont été associées à des relations menant au contact hors ligne. Les auteurs de leurre ayant eu un contact hors ligne avec leurs victimes avaient un plus grand nombre de conversations, en moyenne. Donc, ils avaient plus de temps pour utiliser différentes stratégies pour surpasser les résistances des victimes. Les implications de cette recherche suggèrent que les typologies identifiées dans la littérature scientifique n’ont pas trouver les caractéristiques scientifiquement associées à chacun des types.The advancement of technology created new opportunities for online sex solicitors to cyber victimize minors online (Fortin et al., 2018; Seto et al., 2011). With the increasing number of police reports (Wolak et al., 2012), online sex solicitors pose numerous challenges for police practices. This research project aims to distinguish the differences between the types of interactions that seek offline contact based on the strategies seen in their discourses. By analyzing the differences between the strategies used by various types of interactions, we aimed to identify the strategies which are associated with offline contact interaction group. This study used a combination of qualitative and quantitative research methods to achieve the research goal. We used a qualitative methodology to do a thematic analysis and codify the chatlogs. The strategies used for codification were taken from previous studies and observation of the police data from the Sûreté du Québec . After the codification, we transformed the thematic results into quantitative data. The quantitative research methodology was employed to test the differences in frequency of each strategy between types of interactions. The results demonstrate that the strategies associated with offline contact are persistence, fantasy rehearsal and the presence of opportunities with limited risk of exposure. Contact group used more frequently these strategies compared to the noncontact group. Moreover, contact victims showed more participatory and oppositional behaviours. Offenders who met their victims offline showed longer interactions, on average. Consequentially, offenders from the contact group had more time to use the various strategies to surpass the victims' resistances. The implication of this research lays in the contradiction of these results compared to literature's results. The particularities of each types are not associated with previous typologies

Seriously Social: Making Connections in the Information Age

This thesis is about digital social networks and associated media in the lives of young primarily middle class, people, it based on a qualitative study - using interviews, focus groups and participant observation - of university undergraduates in the United Kingdom and Australia. The study traces how, between 2005 and 2008, these students utilise what I term, 'social media' to manage ?e their social lives. My analysis of the data draws attention to the participatory nature of the technology, and characterises how such resources have become 'everyday' and are seen as essential hubs of information