Orientador: Murilo Cesar Soares / Banca: Raquel Cabral / Banca: Roseane Andrelo / Banca: Eliza Bachega Casadei / Banca: Maria Aparecida Ferrari / Resumo: Em uma sociedade permeada pela incorporação das tecnologias digitais nas diversas ações do cotidiano, a mediatização ganha relevância em outras instâncias, como a dos eventos científicos. Essas ações, pautadas por atividades presenciais, reúnem o público para tratar de temas relacionados às ciências nas distintas áreas do conhecimento. Considerando a mediatização como o conceito que trata das transformações sociais e culturais, resultantes da ubiquidade dos meios de comunicação na sociedade, nos eventos científicos, a inserção das tecnologias digitais tem contribuído para novos formatos dessas ações, bem como novas modalidades de interação. Diante do exposto, este trabalho visa analisar como o processo de mediatização modifica os eventos científicos. Para isso, inicialmente, construímos um referencial teórico pautado no tema dos eventos e mediatização e seus desdobramentos. Para a realização da pesquisa, empregamos o método de estudo de caso, tendo como objeto de pesquisa o XXXIX Congresso Brasileiro de Estudos Interdisciplinares da Comunicação, promovido pela Intercom. De acordo com esse método, realizamos três pesquisas: observação participante no congresso presencial; análise da página do Facebook, criada para o evento e entrevistas com os diretores da Intercom, para, posteriormente fazer a triangulação dos resultados. Os resultados indicam a relevância das atividades presenciais, sob a perspectiva dos debates entre pares, importantes para o aprimoramento dos trabalhos, co... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In a society surrounded by the incorporation of the digital technologies in several daily activities, the mediatization gets its relevancy in other events, like the scientific ones, these events, tied by presential activities, gather the public to deal with themes related to science in different areas of knowledge. Considering the mediatization as a concept that treats the social and cultural transformations as a result of the ubiquity of the communication means in the society, at the scientific events, the insertion of digital technologies has contributed for the format of these new actions, as well as new interaction modalities. Given the above, this paper aims at analyzing how the mediatization process modifies the scientific events. For this, initially, we have built a theoretical referential based on the theme of events, mediatization and its consequences. For the research, we have used a case study method, having as the research object the XXXIX Interdisciplinary Communication Study Brazilian Congress, promoted by Intercom. According to this method, we have performed three researches: observation of the participants at the presential congress; analysis of the Facebook page created for the event and interview with Intercom directors, so that later on the triangulation of results could be made. The results indicate the relevance of the presential activities under the perspective of peer discussions, which are important for the enhancement of the work as well as the experi... (Complete abstract click electronic access below) / Doutor

当今，越来越多的用倾向于使用论坛、博客、脸书等在线工具来表达关于商品、电影和政治等话题的观点。这些观点不仅可以帮助用进行决策，同时也为各个商业和社会领域提供了具有重要价值的反馈信息。因此，面向观点应用成为了当前最活跃的研究领域之一，其中包括观点检索，观点摘要，观点问答。面向观点应用与面向事实应用的根本区别是信息需求的不同，分别是传统的客观信息和主观信息。所谓主观信息是指对于某个特定目标的观点或评论。为了表示主观信息，应该综合考虑观点性、主题相关性，以及观点与主题之间的关联。现有的基于词袋的表示方法将词作为描述客观信息的基本语义单元，它可以有效的表示主题相关性以满足客观信息的需求。而主观信息需要同时考虑观点性和主题相关性，由于单独一个词不能同时表示观点性和相关性，因此词不再是最小的语义单位。此外，基于词袋的表示方法忽略了词序和词义，这使得观点性和相关性两类信息通常混在一起，难以区分。因此，基于词袋方法不能够准确的表示主观信息，并严重的影响了面向观点应用的性能。 / 本文回答了以下几个由主观信息表示不当所引发的研究问题： 1. 对于主观信息而言单个词将不再是基本语义单元，是否存在一种有效的表示方法对其进行描述？ 2. 由于主观信息是观点信息和相关性信息的结合，如何利用新的表示方法来描述这二者之间的关联信息？3. 如何对主观信息进行量化，以便对文档进行检索和分析？ 4. 如何在面向观点应用中实现全新的主观信息表示方法？ / 由于观点检索的结果会直接影响到其它面向观点应用的性能，因此本文从观点检索这一问题入手。首先，我们提出了一种基于句子的方法来分析词袋表示方法的局限性。以此为据，定义了一种具有丰富语义的表达方式来表示主观信息，即词对，它是由出现在同一句子中的情感词和与之关联的目标词共同组成的。然后，我们提出了一系列方法来描述和获取两类语境信息：1）观点内信息：我们给出了三种提取词对的方法以获取观点与主题的关联信息；2）观点间信息：我们提出了一种权重计算方法来度量词对间的相关程度，从而获取词对与词对之间的关系。最后，我们集成了观点内信息和观点间信息并提出了潜在情感关联模型来解决观点检索这一问题。在标准数据集上的实验结果表明，基于词对的表示方法可以有效地描述主观信息，同时潜在情感关联模型能够获取词与词之间的关联信息，从而实现了利用语境信息提高观点检索的效果。 / 此外，我们将词对应用于观点摘要和观点问答中，标准数据集上的评测结果显示基于词对的主观信息表示方法对于其它面向观点应用也同样有效。 / There is a growing interest for users to express their opinions about products, films, politics, by using on-line tools such as forums, blogs, facebooks, etc. These opinions cannot only help users make decisions, e.g., whether to buy a product, but also to ob-tain valuable feedback for business and social events. Today, research on opin-ion-oriented applications (OOAs) including opinion retrieval, opinion summarization and opinion question and answering is attracting much attention. The difference be-tween fact-based and opinion-oriented applications lies in users‘ information need. The former requires objective information and the latter subjective, which comprises of opinions or comments expressed on a specific target. To meet the need of subjective information, both opinionatedness and relevance together with the association between them should be taken into account. Existing systems represent documents in bag-of-word. However, this representation fails to distinguish opinionatedness from relevance. Moreover, due to the ignorance of word sequence, words associations are lost. For this reason, bag-of-word representation is ineffective for subjective information, and affects the performance of OOAs seriously. / In this thesis, we try to answer the following challenging questions arose in subjective information representation. Since word is no longer the basic semantic unit, how would subjective information be represented? Subjective information is a combination of opinionatedness and relevance, so how would the association between them be modeled? How would subjective information be measured for the purpose of document ranking, retrieval, and analysis? How would opinion-oriented applications benefit from subjective information? / We start from solving the problem of opinion retrieval whose results can directly influence the performance of other opinion-oriented applications. We first present a sentence-based approach to analyze the limitation of bag-of-word representation and define a semantically richer representation, namely word pair for subjective infor-mation. A word pair is constructed by a sentiment word and its associated target co-occurring in a sentence. We then propose techniques to capture two kinds of con-textual information. 1) Intra-opinion information: three methods are proposed to ex-tract the word pair. 2) Inter-opinion information: a weighting scheme is present to measure the weight of individual word pair. Finally, we devise an algorithm to integrate both intra-opinion and inter-opinion information into a latent sentimental association model for opinion retrieval. The evaluation on three benchmark datasets suggests the effectiveness of word pair and the latent sentimental association retrieval model provide insight into the words association to support opinion retrieval beneficial from pairwise representation. We also apply word pair to opinion summarization and opinion question answering. The evaluation on two benchmark datasets shows that word pair performs effectively in the applications. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Li, Binyang. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves [96]-103). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Abstract --- p.ii / Abstract in Chinese --- p.iv / Acknowledgements --- p.vi / Contents --- p.viii / List of Tables --- p.xi / List of Figures --- p.xiii / Chapter 1. --- Introduction --- p.1 / Chapter 1.1. --- Problem and Challenges --- p.3 / Chapter 1.1.1 --- Subjective Information Representation --- p.3 / Chapter 1.1.2 --- Associative Information in an Opinion Expression --- p.4 / Chapter 1.1.3 --- Opinion Expression Measurement --- p.5 / Chapter 1.1.4 --- Applications of Subjective Information Representation to Different OOAs --- p.6 / Chapter 1.2. --- Contributions --- p.6 / Chapter 1.3. --- Chapter Summary --- p.7 / Chapter 2. --- Pairwise Representation --- p.9 / Chapter 2.1 --- Related Woks on Opinion Retrieval --- p.10 / Chapter 2.1.1 --- Opinion Retrieval Models --- p.10 / Chapter 2.1.2 --- Lexicon-based Opinion Identification --- p.12 / Chapter 2.2 --- Sentence-based Approach for Opinion Retrieval --- p.13 / Chapter 2.2.1 --- The Limitations of Document-based Approaches for Opinion Retrieval --- p.13 / Chapter 2.2.2 --- Sentence-based Approach for Opinion Retrieval --- p.16 / Chapter 2.2.3 --- Evaluation and Results --- p.21 / Chapter 2.2.4 --- Summary --- p.26 / Chapter 2.3 --- Pairwise Representation --- p.28 / Chapter 2.3.1 --- Definition of Word Pair --- p.28 / Chapter 2.3.2 --- Sentiment Lexicon Construction --- p.29 / Chapter 2.3.3 --- Topic Term Lexicon Construction --- p.30 / Chapter 2.3.4 --- Word Pair Construction --- p.31 / Chapter 2.4 --- Graph-based Model for Opinion Retrieval --- p.33 / Chapter 2.4.1 --- HITS Model for Opinion Retrieval --- p.34 / Chapter 2.4.2 --- PageRank Model for Opinion Retrieval --- p.37 / Chapter 2.4.3 --- Evaluation and Results --- p.40 / Chapter 2.5 --- Chapter Summary --- p.50 / Chapter 3. --- Pairwise Representation Measurement --- p.51 / Chapter 3.1 --- Word Pair Weighting Scheme --- p.52 / Chapter 3.1.1 --- PMI-based Weighting Scheme --- p.52 / Chapter 3.1.2 --- Evaluation and Results --- p.56 / Chapter 3.1.3 --- Summary --- p.60 / Chapter 3.2 --- Latent Sentimental Association --- p.61 / Chapter 3.2.1 --- Problem Formulation --- p.61 / Chapter 3.2.2 --- LSA Integrated Generative Model --- p.62 / Chapter 3.2.3 --- Modeling the Dependency between Q and d --- p.64 / Chapter 3.2.4 --- Modeling the Dependency between O and d --- p.67 / Chapter 3.3 --- Parameter Estimation --- p.67 / Chapter 3.3.1 --- Estimating P(Q --- p.67 / Chapter 3.3.2 --- Estimating MI(Q,O --- p.69 / Chapter 3.4 --- Evaluation and Results --- p.69 / Chapter 3.5 --- Chapter Summary --- p.72 / Chapter 4. --- Pairwise Representation in Opinion-oriented Application --- p.75 / Chapter 4.1. --- Opinion Questioning and Answering --- p.76 / Chapter 4.1.1 --- Problem Statement --- p.76 / Chapter 4.1.2 --- Existing Solution --- p.78 / Chapter 4.1.3 --- A Word Pair based Approach for Sentence Ranking --- p.79 / Chapter 4.1.4 --- Answer Generation --- p.82 / Chapter 4.1.5 --- Evaluation and Results --- p.82 / Chapter 4.2. --- Opinion Summarization --- p.86 / Chapter 4.2.1 --- Problem Statement --- p.86 / Chapter 4.2.2 --- Existing Solution --- p.87 / Chapter 4.2.3 --- Sentence Ranking --- p.88 / Chapter 4.2.4 --- Summary Generation --- p.88 / Chapter 4.2.5 --- Evaluation and Results --- p.89 / Chapter 4.3. --- Chapter Summary --- p.91 / Chapter 5. --- Conclusions and Future Works --- p.93 / Bibliography --- p.97

Successful aging, the ability to resist age-associated illnesses and functional disability, is of increasing importance as the population ages. Studies have shown that exceptionally long-lived individuals fit the successful aging paradigm by compressing disability toward the end of life. This study investigated whether there is evidence of successful cognitive aging in a familial longevity cohort, the Long Life Family Study (LLFS). Part 1 describes the feasibility of conducting a 2.5 hour neuropsychological battery emphasizing episodic memory and executive function, cognitive domains that elicit signs of cognitive dysfunction in relation to normal aging and dementia. The rationale for the selected tests is discussed within the context of minimizing effects from sensory impairments in an aged cohort and optimizing qualitative and quantitative data. In Part 2, the testing of 70 proband generation and 100 offspring generation LLFS participants and 140 generation-matched referent participants without familial longevity is described. Comparison of LLFS proband generation participants with their referent cohort revealed no significant differences in test scores. However, the referent cohort also had more years of education (an important exposure which is discussed in Part 3). LLFS offspring generation participants had borderline significant better performance on a test of executive function (Clock Drawing Test) and attention (Digits Forward) compared with referents. These findings suggest that familial longevity is associated with better cognitive function even at relatively young ages. Continuing to follow these cohorts to older ages may reveal differences in rate of change in cognitive function. Part 3 examines the role of indicators of cognitive reserve. In the proband generation education and participation in mid- and late-life cognitively stimulating activities were found to be higher in the referent cohort. This suggests that people without familial longevity may be more reliant on higher cognitive reserve in order to achieve similar cognitive performance to those from long-lived families. Implications of preserved cognitive function in long-lived families and the effect of cognitive reserve in those without familial longevity are discussed in terms of compression of disability and successful cognitive aging.

Geographies of ageing literature recognises the emotional qualities of ageing. However, an historical tendency to overly medicalise ageing means research often focuses on the emotions associated with specific events such as the emotions involved in living with health-related conditions, being a carer, or being cared for in different settings. There remains a paucity of research that attends to the everyday, mundane emotions of being old. This research attends to this lacuna by drawing on theoretical frames emerging from post-humanism and emotional geographies. Specifically, this research engages with the spatial organisation of emotions as it pertains to an increasingly significant element of ageing: the role of communication technology in older people's ability to create and maintain new modes of (techno)sociability. Drawing upon 29 qualitative interviews and 13 cultural probe follow up responses with retired Londoners aged 59 to 89 years, this research examines how technology connects bodies to objects, people to people and (re)connects older adults to place in new and unexpected ways. Among this participant group diverse, highly individualised and complex amalgams of communication technologies were used. Each mode of communication technology was deployed using intricate strategies of selection and implementation, based on varying temporalities and spatialities, enhancing the ability of participants to relate emotionally with others. Technology use in this regard enabled the portability and emotional continuity of social networks, as communication was no longer tied to certain physical spaces. These findings are theoretically significant as emotions are increasingly seen to have a direct impact on the spatial construction of society through shaping human capacities and behaviours, which form the world around us. Work in this domain has been limited with certain emotions and bodies being more readily researched, and affiliated with particular gendered and sexualised bodies, bodily capacities, physical forms and social identities than others. This research is able to offer an understanding not currently present in geographical literatures, and offer new modes of spatial analysis that take into account the pervasive but differentiated use of technology.

行为经济学试图分析决策过程对经济行为和结果的影响。我的博士论文由四篇独立的论文组成，运用经济学和心理学的理论视角，研究了个人和群体的决策和行为模式。本论文探讨的问题包括建立社会关系的过程中交互性的影响、队列中的信息外部性、群体决策中较差决定的概率支配、引领型消费者和追随型消费者的不同行为模式等。 / 在题为“社会资本与电信客流失：移动网络中交互性“的第一篇论文中， 我实证检验交互性在发展社会关系中的作用。基于包括网络连接度、社会关系强度、交互性等社会资本要素，我设计了一种预测电信客流失的方法。该算法基于源自用电信服务数据的社会资本度量和服务状态，因此它能较为容易的运用于现实数据库和客关系管理。 / 在题为“一种顺序行为中的信息积累模型“的第二篇论文中，我研究了顺序模式的社会学习过程，提出了一种基于多阶段决策过程的度量信息积累程度和评介信息瀑布稳定性的数学模型。理论结果反映了信息瀑布中行为模式的两个主要特征：信息积累和边际效应递减。 / 在题为“社会学习和群体的智慧：网络中的同步行为“的第三篇论文中，我分析了个人行为通过学习策略在网络中蔓延的现象。这种基于网络的同步学习是通过仿真和数值实验得到了直观的。本研究证明，网络中的同步学习对个体和群体表现有促进作用。同时，其促进的程度是存在阈值的。 / 在题为“社会化媒体中的学习：社会化线索与决策偏差“的第四篇论文中, 我通过分析网络爬虫收集的互联网数据，探讨了社会化媒体中学习策略的影响。这项研究表明，流行性产品的选择中起主导作用的是社会化线索。社会化线索放大了产品之间的销量的差异。此外，我还发现了社会化线索的两种不对称性：（1）社会学习过程中人们对长期变化和短期变化的非对称敏感性；（2）领导型用和追随型用提供好坏口碑的非对称性。这些发现表明，社会线索在决策过程中是存在偏差的。 / Behavioral economics tries to understand the impact of decision process on economic behaviors and outcomes. Utilizing theoretical lenses of psychology and economics, my dissertation, composed of four essays, studies the behavioral pattern of individuals and groups to tell philosophies behind some interesting phenomena, such as reciprocity in developing social relations, information externality in queues, probable dominance of collectively bad decisions, the contradicting behavioral pattern of leaders and followers when facing bad choices, and etc. / In my first essay entitled “Social Capital and Telecom Churn: Reciprocity in Mobile Telecom Networks“, I empirically examine the role of reciprocity in the development of social relations. Based on multiple dimensions of social capital, e.g., network connectivity, social tie strength, internal network ratio, and reciprocity, I develop a method to predict telecom churns. The algorithm is based on social capital derived from historical usage patterns and service status, thus it is easy to be implemented with customer database. / In my second essay entitled “A Model of Information Aggregation in Sequential Moves“, I investigate sequential learning process and propose a mathematical model that measure information aggregation and evaluate the stability of informational cascades with a multi-stage decision process. The results capture two primary behavioral aspect of informational cascade: information aggregation and diminishing sensitivity. / In my third essay entitled “Social Learning and the Wisdom of Crowd: Simultaneous Moves in Network“, I investigate the phenomenon of social contagion through learning strategies among individuals in the network. This network-based simultaneous learning process is simulated via computer programme to seek insights on the effect of simultaneous learning on collective and individual actions. Through numerical experiment, it demonstrats that learning in network can be effective while bad decisions have chance to dominate, and there is a threshold for collective decision quality. / In my forth essay entitled “Learning in Social Media: Social Cues and Decision Biases“, I investigate the effect of learning strategy in the context of social media with internet usage dataset collected by web crawler. This study demonstrates that choices based on social cues dominate for popular products, and it exaggerates the inequality among products. Besides, two types of asymmetries exist for social cues: (1) Asymmetric sensitivity for immediate and accumulative changes in social learning process; and (2) Asymmetric behavioral pattern in providing WOMs for leaders and followers. These findings suggest that social cues may be biased. / Essay 1. Social capital and telecom churn: reciprocity in mobile telecom networks -- essay 2. A cognitive model of information aggregation in sequential moves -- essay 3. Social learning and the wisdom of crowd: simultaneous moves in network -- essay 4. Learning in social media: social cues and decision biases. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Hu, Hao. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references. / Abstracts also in Chinese. / PREFACE --- p.1 / SOCIAL CAPITAL AND TELECOM CHURN: RECIPROCITY IN MOBILE TELECOM NETWORKS --- p.6 / Chapter 1. --- INTRODUCTION --- p.7 / Chapter 2. --- LITERATURE REVIEW --- p.7 / Chapter 2.1. --- Service Continuity and Churn --- p.7 / Chapter 2.2. --- Social Capital in the Network --- p.9 / Chapter 3. --- THEORETICAL FRAMEWORK --- p.11 / Chapter 3.1. --- Network Connectivity --- p.12 / Chapter 3.2. --- Social Tie Strength --- p.12 / Chapter 3.3. --- Internal Network Ratio --- p.13 / Chapter 3.4. --- Reciprocal Social Norm --- p.13 / Chapter 3.5. --- Service Continuity and Churn --- p.14 / Chapter 4. --- EMPIRICAL ANALYSIS --- p.14 / Chapter 4.1. --- Research Setting and Data Collection --- p.14 / Chapter 4.2. --- Variables and Proxies --- p.14 / Chapter 4.3. --- Social Capital and Service Continuity --- p.17 / Chapter 4.4. --- Service Continuity and Churn --- p.20 / Chapter 5. --- PREDICTIVE MODEL FOR TELECOM CHURN --- p.21 / Chapter 5.1. --- Performance Assessment Criteria --- p.21 / Chapter 5.2. --- Bench Mark Model --- p.21 / Chapter 5.3. --- Three-Stage Model --- p.23 / Chapter 6. --- DISCUSSION AND CONCLUDING REMARKS --- p.25 / Chapter 6.1. --- Theoretical Extension --- p.25 / Chapter 6.2. --- Managerial Implication --- p.26 / Chapter APPENDIX I --- MEASUREMENT CLASSIFICATION --- p.27 / Chapter APPENDIX II --- DATA DESCRIPTION --- p.28 / REFERENCES --- p.30 / A COGNITIVE MODEL OF INFORMATION AGGREGATION IN SEQUENTIAL MOVES --- p.32 / Chapter 1. --- INTRODUCTION --- p.33 / Chapter 2. --- THEORETICAL FRAMEWORK --- p.34 / Chapter 2.1. --- Conceptual Background --- p.34 / Chapter 2.2. --- Decision Scenarios --- p.35 / Chapter 2.3. --- Hypothesis --- p.38 / Chapter 3. --- ANALYTICAL MODEL --- p.40 / Chapter 3.1. --- Model Setup --- p.40 / Chapter 3.2. --- Sequential Analysis --- p.41 / Chapter 4. --- NUMERICAL ANALYSIS --- p.43 / Chapter 4.1. --- Margin Analysis --- p.43 / Chapter 4.2. --- Product Complexity --- p.44 / Chapter 4.3. --- Information Revealing --- p.46 / Chapter 5. --- CONCLUSION --- p.47 / Chapter References --- p.48 / SOCIAL LEARNING AND THE WISDOM OF CROWD: SIMULTANEOUS MOVES IN NETWORK --- p.50 / Chapter 1. --- INTRODUCTION --- p.51 / Chapter 2. --- THE PARADIGM OF A NESTED WORLD --- p.52 / Chapter 2.1. --- Bounded Rationality and Social Learning --- p.53 / Chapter 2.2. --- Social Learning and Conformity tendency --- p.54 / Chapter 2.3. --- Summary - Judgment and Collective Behavior --- p.55 / Chapter 3. --- THEORETICAL FRAMEWORK --- p.56 / Chapter 3.1. --- Primary Investigation --- p.57 / Chapter 3.2. --- Secondary Investigation --- p.61 / Chapter 4. --- RESEARCH METHODOLOGY --- p.62 / Chapter 4.1. --- Construct Measures --- p.62 / Chapter 4.2. --- Computational Model --- p.64 / Chapter 4.3. --- Numerical Experiment --- p.67 / Chapter 4.4. --- Pattern Analysis --- p.68 / Chapter 5. --- CONCLUSION --- p.73 / Chapter 6. --- IMPLICATION --- p.74 / REFERENCES --- p.75 / LEARNING IN SOCIAL MEDIA: SOCIAL CUES AND DECISION BIASES --- p.78 / Chapter 1. --- INTRODUCTION --- p.79 / Chapter 2. --- RESEARCH BACKGROUNDS --- p.81 / Chapter 2.1. --- Social Cues and Choices --- p.81 / Chapter 2.2. --- Decision Biases of Social Cues --- p.82 / Chapter 3. --- HYPOTHESES --- p.83 / Chapter 3.1. --- Comparative Impact of Social Cues --- p.84 / Chapter 3.2. --- Reference Dependence in Social Learning --- p.85 / Chapter 3.3. --- WOM Driven by Leaders Confirmatory Bias and Followers Regret --- p.86 / Chapter 4. --- RESEARCH METHODOLOGY --- p.87 / Chapter 4.1. --- Data Summary --- p.88 / Chapter 4.2. --- Empirical Analysis --- p.89 / Chapter 5. --- DISCUSSION AND CONCLUDING REMARKS --- p.94 / REFERENCES --- p.95

Online health communities (OHCs) have been increasingly popular among patients with chronic or life-threatening illnesses for the exchange of social support. Contemporary research of OHCs relies on methods and tools to handle analytics of massive user-generated content at scale to complement traditional qualitative analysis. In this thesis, we aim at advancing the area of research by providing computational tools and methods which facilitate automated content analysis, and by presenting applications of these tools to investigating member characteristics and behaviors. We first provide a framework of conceptualization to systematically describe problems, challenges, and existing solutions for OHCs from a social support standpoint, to bridge the knowledge gap between health psychology and informatics. With this framework in hand, we define the landscape of online social support, summarize current research progress of OHCs, and identify research questions to investigate for this thesis. We then build a series of computational tools for analyzing OHC content, relying on techniques of machine learning and natural language processing. Leveraging domain-specific features, our tools are tailored to handle content analysis tasks on OHC text effectively. Equipped with computational tools, we demonstrate how characteristics of OHC members can be identified at scale in an automated fashion. In particular, we build up multi-dimensional descriptions for patient members, consisting of what topics they focus on, what sentiment they express, and what treatments they discuss and adopt. Patterns of how these member characteristics change through time are also investigated longitudinally. Finally, relying on computational analytics, members' behaviors of engagement such as debate and dropping-out are identified and characterized. Studies presented in this thesis discover static and longitudinal patterns of member characteristics and engagement, which are potential research hypotheses to be explored by health psychologists and clinical researchers. The thesis also contributes to the informatics community by making computational tools, lexicons, and annotated corpora available to facilitate future research.

The overarching goal of the present research is to gain a better understanding of mechanisms that shape our interpersonal ties and social networks by investigating their associated brain bases in naturally occurring groups. All three studies rely on a novel round-robin neuroimaging paradigm that incorporates group members as both participants in the fMRI scanner (perceivers) and stimuli (targets) presented during a naturalistic face-viewing task. Study 1 elucidates how group members’ popularity is tracked by neural systems underlying valuation (i.e., processing reward value and evaluating others’ motivational significance), which in turn engage social cognition systems that facilitate understanding others’ mental states. Individual differences in the sensitivity of this neural mechanism are examined and found to correlate with perceivers’ own popularity. Studies 2 and 3 extend the paradigm developed in Study 1 to incorporate social network data collected in a longitudinal context, and further test whether neural measures collected during the initial stages of group formation can prospectively predict group members’ future liking ties (Study 2) and social network centrality (Study 3). In Study 2, neural activity in the aforementioned valuation systems predicts newly acquainted group members’ future—but not current—idiosyncratic liking of one another. Further analyses suggest this effect reflects only one facet of a far more nuanced interpersonal phenomenon implicated in the eventual emergence of dyadic liking reciprocity: individuals’ initial liking preferences are not personally tracked by their own brains’ idiosyncratic valuation responses to particular group members, but rather interpersonally tracked by the neural valuation responses they uniquely evoke in those particular group members; moreover, each dyad member’s idiosyncratic valuation activity influences both their own and each other’s future liking. Having established in Studies 1 and 2 a paradigm for measuring how social network members implicitly evaluate one another, Study 3 extends it to include oneself (i.e., the perceiver) as an evaluate target of social perception. Revisiting the Study 1 social network members’ data, enhanced valuation activity in response to oneself (relative to others) correlates positively with questionnaire measures of dispositional narcissism (but not self-esteem) and negatively with sociometric popularity. Using the data from Study 2, the trait narcissism effect is replicated and extended to a context in which the “others” are newly acquainted group members. This longitudinal data also reveals that the neural measure of narcissistic self-valuation prospectively predicts future (un)popularity, even controlling for initial levels of popularity. Considered together, this research aims to integrate conceptual and methodological frameworks across social psychology (e.g., round-robin experimental designs), cognitive neuroscience (e.g., fMRI), and sociology (e.g., social network analysis).

Social support is classically conceptualized as “what you can do” or “what you can offer” to support someone in times of stress. But for some individuals, could less be more when it comes to social support? Empirical research has shown that support receipt can have differential effects. A preference for self-reliance in stressful situations might be one explanation as to why social support is not always beneficial for some individuals. The current work introduces the phenomenon that some people prefer to be self-reliant in times of stress, i.e., they want to independently deal with the stressor instead of receiving direct supportive acts from a partner or someone else. Across seven studies, within three unique populations, and through low and high stress periods, we aimed to understand individual differences in a preference for self-reliance within close relationships. We discovered that a preference for self-reliance is a common phenomenon from adolescence through adulthood. This preference matters at a daily level across different outcomes and relationships, and is an integral part of daily human interaction affecting support transactions across different support providers. People with certain personality traits may be more likely to prefer self-reliance. The interaction between a preference for self-reliance and social support provision has important implications during critical time periods such as the college application process. Times of acute stress are particularly revealing of links between a preference for self-reliance and support transactions. Wanting to be self-reliant in stressful situations may be a more common desire than previously thought in the literature on close relationships. Individual differences such as the preference for self-reliance may explain the mixed effects of social support. The addition of preference for self-reliance as an individual difference impacting support transactions expands the field’s current understanding of social support and support provision. We now know that there is a desired form of support beyond the classic conceptualization of social support and, for some, less is in fact more.

The ways that individuals socialize within groups have evolved to overcome challenges relevant to species-specific socioecology and individuals’ life history state. Studying the drivers, proximate benefits, and fitness consequences of social interaction across life stages therefore helps clarify why and how social behavior has evolved. To date, juvenility is one life stage that field researchers have largely overlooked; however, individual experiences during development are relevant to later behavior and ultimately to fitness. Juvenile animals are subject to unique challenges related to their small size and relative inexperience. They are likely to employ behavioral strategies to overcome these challenges, while developing adult-like behavioral competence according to their species and sex. The research presented in this dissertation draws from long-term behavioral records of adult females and shorter-term behavioral records of juveniles from a population of blue monkeys (Cercopithecus mitis stuhlmanni) in western Kenya. I combine data on social behavior, demography, and biomarkers related to energetic and metabolic status, to assess both short and long term corollaries of social strategies in this gregarious Old World primate. I first explored whether the quality of social ties predicted longevity among adult female blue monkeys. Controlling for any effects of dominance rank, group size, and life history strategy on survival, I used Cox proportional hazards regression to model the both the cumulative and current relationship of social ties and the hazard of mortality in 83 wild adult females of known age, observed 2-8 years each (437 subject-years) in 8 social groups. The strength of bonds with close partners increased mortality risk under certain conditions: females that had strong bonds with partners that were inconsistent over multiple years had a higher risk of mortality than females adopting any other social strategy. Within a single year, females had a higher risk of mortality if they were strongly bonded with partners that were inconsistent from the previous year vs. with partners that were consistent. Dominance rank, number of adult female group-mates, and age at first reproduction did not predict the risk of death. This study demonstrates that costs and benefits of strong social bonds during adulthood can be context-dependent, relating to the consistency of social partners over time. To understand the adaptive value of social behavior among juveniles, it was first necessary to understand the conditions under which their social behavior occurred and with which it co-varied. I examined the social behavior of 41 juvenile blue monkeys, using data collected over 8 consecutive months. I analyzed variation in social activity budgets and partner number related to life history characteristics, socio-demographic conditions, and seasonal environmental change. I examined partner preferences according to kinship, and relative age and rank. Lastly, I explored the stability of juvenile social tendencies over time. Males and females differed strongly in their social activity budgets and partner numbers: males spent more time playing with more partners than females, whereas females spent more time grooming and sitting close with more partners than males. Nevertheless, they were much more similar in terms of their partner preferences. Juveniles generally preferred to interact with partners with whom they were closely related and that were similar in age and maternal rank. Juveniles’ affiliative and aggressive behavior varied seasonally, suggesting that these two types of behavior were related. Rates of agonism given and received were the only types of social behavior to demonstrate repeatable inter-individual differences. This analysis provides a comprehensive examination of juvenile behavior in blue monkeys, synthesizing findings with those in other primate and non-primate species. I then explored the short-term costs and benefits of juveniles’ sociality in terms of their effects on allostatic load. I examined variation in energy balance (as measured by urinary C-peptide), social style, and their influences on allostatic load (as measured by fecal glucocorticoid metabolites, fGCs). Juvenile energy balance varied according to sex, availability of ripe fruit, and rainfall. Both energy balance and social style predicted fGC levels, such that juveniles that had a higher energy balance, groomed less, and played more had lower fGCs. Time spent grooming interacted with energy balance in their effect on fGCs, such that individuals with higher energy balance actually had higher fGCs the more time they groomed. Neither maternal rank nor involvement in agonism corresponded with juvenile fGC levels. These results suggest that juvenile blue monkeys experience energetic stressors and that navigating the social environment via overt affiliative behavior, namely grooming, is a potentially stress-inducing endeavor. Lastly, to further understand variation in social behavior during juvenility, I explored the role of mothers in shaping juveniles’ affiliative tendencies. I examined whether the social behavior of juvenile animals resembled that of their mothers and whether their social behavior was subject to maternal effects, using data from the 41 juveniles and their 29 mothers. Juveniles’ grooming time with peers corresponded with the amount of time they groomed with (primarily being groomed by) mothers as infants, and this relationship varied by sex. Females spent less time grooming with peers the more maternal grooming they received during infancy, whereas males groomed with peers more. The time juveniles spent in other types of association with partners did not correspond with the same behavior in mothers, nor were other types of association subject to maternal effects. This exploratory study suggests limited effects of maternal behavior during infancy, but also that females and males respond differently to maternal investment during the first year. The results of this dissertation emphasize the importance of long-term studies of natural populations in understanding the evolution of social behavior, particularly when examining the causes and consequences of social ties over the life cycle in a long-lived animal. Strategies of affiliation did indeed correspond with costs and benefits over the life cycle, as they were relevant both to mortality in female adults and metabolic hormones among juveniles. Further, individuals socialize during development according to their life trajectory as male or female, what seasonal changes in the physical environment require or allow, and early-life maternal effects.

Social psychologists have long been interested in understanding behavior as a function of both individuals and the social structures in which they are embedded. However, since the cognitive revolution of the 1960s, processes internal to individuals have received greater attention than structural influences. This dissertation examines how networks may shape important real-world outcomes beyond intrapsychic phenomena across three studies in varied contexts. In doing so, this work suggests that the networks to which people belong—whether networks of social ties or networks of information—provide both affordances and constraints that affect behavior and outcomes. Chapter I provides a brief introduction to social network analysis as a set of theoretical, methodological, and analytical tools. Chapter II examines the gender gap in negotiation performance. Findings suggest that disparities between male and female MBA students in class social network positions predict this gap more strongly than intrapsychic mechanisms more commonly studied, such as apprehension about negotiating and stereotype threat. Chapter III examines how students’ social networks promote persistence over time in a high-stress science, technology, engineering, and math (STEM) setting. This chapter pulls social network analysis into an experimental context by examining the effects of a randomly assigned social psychological intervention on students’ social networks and subsequent persistence in the biosciences. Chapter IV approaches networks from a different angle, examining how online news media are organized into network structures that may contribute to selective exposure to homogenous information. Finally, Chapter V discusses implications of these three studies. Specifically, I discuss implications for education research, intervention science, and the growing area of social network psychology.