In concept, online communities allow people to access the wide range of knowledge and abilities of a heterogeneous group of users. In reality, current implementations of various online communities suffer from a lack of participation by the most qualified users. The participation of qualified users, or experts, is crucial to the social welfare and widespread adoption of such systems. This research proposes techniques for identifying the most valuable contributors to several classes of online communities, including question and answer (QA) forums and other content-oriented social networks. Once these target users are identified, content recommendation and novel quantitative incentives can be used to encourage their participation. This research represents an in-depth investigation into QA systems, while the major findings are widely applicable to online communities in general. An algorithm for recommending content in a QA forum is introduced which can route questions to the most appropriate responders. This increases the efficiency of the system and reduces the time investment of an expert responder by eliminating the need to search for potential questions to answer. This recommender is analyzed using real data captured from Yahoo! Answers. Additionally, an incentive mechanism for QA systems based on a novel class of incentives is developed. This mechanism relies on systemic rewards, or rewards that have tangible value within the framework of the online community. This research shows that human users have a strong preference for reciprocal systemic rewards over traditional rewards, and a simulation of a QA system based on an incentive that utilizes these reciprocal rewards outperforms a leading incentive mechanism according to expert participation. An architecture is developed for a QA system built upon content recommendation and this novel incentive mechanism. This research shows that it is possible to identify the most valuable contributors to an online community and motivate their participation through a novel incentive mechanism based on meaningful rewards. / text

published_or_final_version / abstract / Social Work and Social Administration / Master / Master of Philosophy

published_or_final_version / abstract / toc / Asian Studies / Doctoral / Doctor of Philosophy

No description available.

Web and mobile technologies have had such profound impact that we have witnessed significant evolutionary changes in our social, economic and cultural activities. In recent years, online social networking sites such as Twitter, Facebook, Google+, and LinkedIn have gained immense popularity. Such social networks have led to an enormous explosion of network-centric data in a wide variety scenarios, posing unprecedented analytical and computational challenges to MIS researchers. At the same time, the availability of such data offers major research opportunities in various social computing and analytics areas to tackle interesting questions such as: - From a business and marketing perspective, how to mine the novel datasets of online user activities, interpersonal communications and interactions, for developing more successful marketing strategies? - From a system development perspective, how to incorporate massive amounts of available data to assist online users to find relevant, efficient, and timely information? In this dissertation, I explored these research opportunities by studying multiple analytics problems arose from the design and use of social networking services. The first two chapters (Chapter 2 and 3) are intended to study how social network can help to derive a better estimation of customer lifetime value (CLV), in the social gaming context. In Chapter 2, I first conducted an empirical study to demonstrate that friends' activities can serve as significant indicators of a player's CLV. Based on this observation, I proposed a perceptron-based online CLV prediction model considering both individual and friendship information. Preliminary results have shown that the model can be effectively used in online CLV prediction, by evaluating against other commonly-used benchmark methods. In Chapter 3, I further extended the metric of traditional CLV, by incorporating the personal influences on other customers' purchase as an integral part of the lifetime value. The proposed metric was illustrated and tested on seven social games of different genres. The results showed that the new metric can help marketing managers to achieve more successful marketing decisions in user acquisition, user retention, and cross promotion. Chapter 4 is devoted to the design of a recommendation system for micro-blogging. I studied the information diffusion pattern in a micro-blogging site (Twitter.com) and proposed diffusion-based metrics to assess the quality of micro-blogs, and leverage the new metric to implement a novel recommendation framework to help micro-blogging users to efficiently identify quality news feeds. Chapter 5 concludes this dissertation by highlighting major research contributions and future directions.

No description available.

Cultural capital facilitators are an unexplored phenomenon in the higher education literature despite their crucial presence on community college campuses. Through the use of social capital theory, social networks, and cultural capital theory, this study explores the role that cultural capital facilitators play in first-generation, community college student information acquisition and ultimate success. Multiple qualitative methods are utilized to discover the cultural capital facilitator characteristics and attributes, social networks and types of cultural capital information shared between first-generation students and cultural capital facilitators. Implications for community college practitioners are also presented in terms of the role that classroom instructors play as cultural capital facilitators as well as the characteristics and attributes that these individuals can acquire through professional development opportunities. Finally, the interconnectedness of cultural capital facilitators' social networks and the domination of academic, cultural capital information are elaborated on for community college personnel in their examination of structural and functional barriers to first-generation student success.

The aim of the present thesis is to examine various aspects of the school-class structure and their links to health in a life-course perspective. The empirical studies are based on two longitudinal data materials of cohorts born in the 1950s, followed up until middle age. In the first study, the overall status distribution in the school class was shown to be associated with both minor psychiatric disorder in childhood and self-rated health in adulthood. Thus, ill-health was more common among individuals who attended school classes less equal in terms of status. The second study demonstrated that it was more common among those who had fewer mutual friendships in the school class to report poorer health as adults. Socioeconomic career emerged as the primary explanation for men while, for women, these findings were largely unaccounted for by any of the included child and adult circumstances. Findings from the third study suggested the child’s status position in the school class, i.e. peer status, to be related to a wide range of health outcomes in adulthood. In particular, lower peer status was linked to an excess risk of mental and behavioural disorders, cardiovascular diseases and diabetes. Childhood social class did not confound these associations to any large extent. The fourth study examined two types of social isolation in the school class: marginalisation (low peer status) and friendlessness. Hospitalisation due to any disease was more common among marginalised children compared to among non-isolates, whereas no corresponding association was found for the friendless. For both types of isolates, the number of hospitalisations was greater than among non-isolated individuals. Of the studied childhood factors, scholastic ability emerged as an important mechanism. In sum, this thesis points to the relevance of the school class for health development across the life course and to the complexity of pathways through which influences of the school class may operate. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Submitted. Paper 2: Accepted.

The number of unaccompanied asylum-seeking children (UASC) has increased significantly in Sweden since the summer of 2006. Due to Sweden’s high rate of asylum application approvals, it has become a main destination country. Concurrently, unaccompanied asylum-seeking children have decreased in other more traditional European destination countries, such as Germany, the United Kingdom, Belgium, the Netherlands and Norway. The majority of the UASC come from Afghanistan and Somalia. There is insufficient knowledge regarding these children’s reasons and patterns for the migration to Sweden. This is a case study based on semi-structured interviews with key informants that have been strategically chosen for this study. The Migration System theory, which is based on key mechanisms of the globalization theory, is used in this study. Restricted asylum regulations in Western countries have created a “migratory industry” with human smugglers, which facilitate and expand the irregular migration. The migratory industry greatly influences the children’s choice of destination. Without the assistance of human smugglers, a migration would be impossible for these children. The conclusion of this study demonstrates the importance of informal social networks that are the reason behind the increase of UASC in Sweden.

This study explored the social networks and social support of parents in Embo and Molweni, two villages of KwaDedangendlale outside Durban. The study is part of a larger South African project, CHAMP-SA (Collaborative HN/AIDS Adolescent Mental Health Project). CHAMP-SA is an adaptation of CHAMP which originated in the USA. CHAMP works with pre-adolescents and their families in addressing parenting issues with the aim of re-establishing the adult protective shield for these children. The current study evaluates the social network component of the pilot phase of CHAMP-SA. The first part of the current study was quantitative and employed a repeated measures quasi-experimental design intervention with both the experimental and control groups. The second, qualitative part used individual interviews to interrogate the results of the quantitative data. Content analysis was used to determine what factors impeded or enhanced the process of social networking. Bronfenbrenner's Systemic Ecological Theoretical Model was used to understand these at a personal, interpersonal and community level. / Thesis (M.A.)-University of KwaZulu-Natal, Durban, 2005.