Den växande globala användningen av sociala medier skapar enorma mängder social data online, kallat för Big Social Data (BSD). Tidigare forskning lyfter problem med att BSD ofta har bristande tillförlitlighet som underlag vid beslutsfattande och att det är starkt kopplat till dataoch informationskvalitet. Det finns dock en avsaknad av forskning som redogör för praktikers perspektiv på detta. Därför undersökte denna studie vad som upplevs problematiskt kring transformation av BSD till tillförlitlig information för beslutsfattande i en organisationskontext, samt hur detta skiljer sig i teori jämfört med praktik. En fallstudie gjordes av mjukvaruföretaget SAS Institute (SAS). Datainsamlingen genomfördes via intervjuer samt insamling av dokument och resultaten analyserades kvalitativt. Studien gjorde många intressanta fynd gällande upplevda problem kopplat till transformation av BSD, bl.a. hög risk för partisk data och låg analysmognad, samt flera skillnader mellan teori och praktik. Tidigare forskning gör inte heller skillnad mellan begreppen datakvalitet och informationskvalitet, vilket görs i praktiken. / The growing use of social media generates enormous amounts of online social data, called Big Social Data (BSD). Previous research highlights problems with BSD reliability related to decision making, and that reliability is strongly connected to data quality and information quality. However, there is a lack of research with a focus on practitioners’ perspectives on this matter. To address this gap, this study set out to investigate what is perceived as a problem when transforming BSD into reliable information for decision making in an organisational context, and also how this differs in theory compared with practice. A case study was conducted of the software company SAS Institute (SAS). Data collection was done through interviews and gathering of documents, and results were analysed qualitatively. The study resulted in many interesting findings regarding perceived problems connected to the transformation of BSD, e.g. high risk of biased data and low maturity regarding data analysis, as well as several differences between theory and practice. Furthermore, previous research makes no distinction between the terms data quality and information quality, but this is done in practice.

Extraire l'opinion publique en analysant les Big Social data a connu un essor considérable en raison de leur nature interactive, en temps réel. En effet, les données issues des réseaux sociaux sont étroitement liées à la vie personnelle que l’on peut utiliser pour accompagner les grands événements en suivant le comportement des personnes. C’est donc dans ce contexte que nous nous intéressons particulièrement aux méthodes d’analyse du Big data. La problématique qui se pose est que ces données sont tellement volumineuses et hétérogènes qu’elles en deviennent difficiles à gérer avec les outils classiques. Pour faire face aux défis du Big data, de nouveaux outils ont émergés. Cependant, il est souvent difficile de choisir la solution adéquate, car la vaste liste des outils disponibles change continuellement. Pour cela, nous avons fourni une étude comparative actualisée des différents outils utilisés pour extraire l'information stratégique du Big Data et les mapper aux différents besoins de traitement.La contribution principale de la thèse de doctorat est de proposer une approche d’analyse générique pour détecter de façon automatique des tendances d’opinion sur des sujets donnés à partir des réseaux sociaux. En effet, étant donné un très petit ensemble de hashtags annotés manuellement, l’approche proposée transfère l'information du sentiment connue des hashtags à des mots individuels. La ressource lexicale qui en résulte est un lexique de polarité à grande échelle dont l'efficacité est mesurée par rapport à différentes tâches de l’analyse de sentiment. La comparaison de notre méthode avec différents paradigmes dans la littérature confirme l'impact bénéfique de notre méthode dans la conception des systèmes d’analyse de sentiments très précis. En effet, notre modèle est capable d'atteindre une précision globale de 90,21%, dépassant largement les modèles de référence actuels sur l'analyse du sentiment des réseaux sociaux. / Extracting public opinion by analyzing Big Social data has grown substantially due to its interactive nature, in real time. In fact, our actions on social media generate digital traces that are closely related to our personal lives and can be used to accompany major events by analysing peoples' behavior. It is in this context that we are particularly interested in Big Data analysis methods. The volume of these daily-generated traces increases exponentially creating massive loads of information, known as big data. Such important volume of information cannot be stored nor dealt with using the conventional tools, and so new tools have emerged to help us cope with the big data challenges. For this, the aim of the first part of this manuscript is to go through the pros and cons of these tools, compare their respective performances and highlight some of its interrelated applications such as health, marketing and politics. Also, we introduce the general context of big data, Hadoop and its different distributions. We provide a comprehensive overview of big data tools and their related applications.The main contribution of this PHD thesis is to propose a generic analysis approach to automatically detect trends on given topics from big social data. Indeed, given a very small set of manually annotated hashtags, the proposed approach transfers information from hashtags known sentiments (positive or negative) to individual words. The resulting lexical resource is a large-scale lexicon of polarity whose efficiency is measured against different tasks of sentiment analysis. The comparison of our method with different paradigms in literature confirms the impact of our method to design accurate sentiment analysis systems. Indeed, our model reaches an overall accuracy of 90.21%, significantly exceeding the current models on social sentiment analysis.

In den letzten Jahren haben Innovationen bei Datenquellen und Methoden für die sozialwissenschaftliche Forschung zugenommen. Diese Forschungsarbeit zielt darauf ab, die Auswirkungen dieser Innovationen auf drei Praxisgemeinschaften besser zu verstehen: qualitativ Forschende, Big Social Data Forschende und Datenkurator*innen. Folgenden Forschungsfragen werden behandelt. RQ1: Wie unterscheidet sich die Kuratierung von Big Social Data und qualitativen Daten? RQ2: Welche Auswirkungen haben diese Ähnlichkeiten und Unterschiede auf die Kuratierung von Big Social Data und qualitativen Daten und was können wir aus der Kombination dieser beiden Communities lernen? Ich beantwortete diese Fragen durch eine Literaturrecherche, in der ich Gemeinsamkeiten zwischen qualitativer Datennachnutzung und Big Social Data identifizierte. Dann führte ich semi-strukturierte Interviews mit den drei Praxisgemeinschaften durch. Die Analyse identifizierte sechs Schlüsselthemen für die qualitative Datennachnutzung und Big Social Data: Kontext, Datenqualität und Vertrauenswürdigkeit, Datenvergleichbarkeit, informierte Einwilligung, Datenschutz und Vertraulichkeit sowie geistiges Eigentum und Dateneigentum. Ich habe außerdem fünf weitere Themen identifiziert: Domänenunterschiede, Strategien für eine verantwortungsvolle Praxis, Fragen der Datenpflege, Menschen oder Inhalte als Untersuchungsobjekte sowie unterschiedliche Schwerpunkte und Ansätze. Die Verbindung dieser drei Praxisgemeinschaften kann ein breiteres Verständnis der Schlüsselfragen unterstützen und zu verantwortungsbewussteren Forschungspraktiken führen. Datenkurator*innen verfügen über die Fähigkeiten und Perspektiven, um zwischen den Praxisgemeinschaften zu übersetzen und eine verantwortungsvolle qualitative Nachnutzung von Daten und Big Social Data zu unterstützen. / Recent years have seen the rise of innovations in data sources and methods for social science research. This research aims to better understand the impact of these innovations on three communities of practice: qualitative researchers, big social researchers, and data curators. I address the following research questions. RQ1: How is big social data curation similar to and different from qualitative data curation? RQ1a: How are epistemological, ethical, and legal issues different or similar for qualitative data reuse and big social research? RQ1b: How can data curation practices support and resolve some of these epistemological and ethical issues? RQ2: What are the implications of these similarities and differences for big social data curation and qualitative data curation, and what can we learn from combining these two conversations? I answered these questions through a literature review, in which I identified issues in common between qualitative data reuse and big social research. Then I conducted semi-structured interviews with the three communities of practice. The research identified six key issues for qualitative data reuse and big social research: context, data quality and trustworthiness, data comparability, informed consent, privacy and confidentiality, and intellectual property and data ownership. I also identified five additional themes: domain differences, strategies for responsible practice, data curation issues, human subjects vs. content, and different focuses and approaches. Connecting these three communities of practice can support a broader understanding of the key issues and lead to more responsible research practices. Data curators have the skills and perspectives to translate between communities of practice and provide guidance for responsible qualitative data reuse and big social data.

The influence of Information and Communication Technologies (ICTs) particularly internet technology has had a fundamental impact on the way government is administered, provides services and interacts with citizens. Currently, the use of social media is no longer limited to informal environments but is an increasingly important medium of communication between citizens and governments. The extensive and increasing use of social media will continue to generate huge amounts of user-generated content known as Big Social Data (BSD). The growing body of BSD presents innumerable opportunities as well as challenges for local government planning, management and delivery of public services to citizens. However, the governments have not yet utilised the potential of BSD for better understanding the public and gaining new insights from this new way of interactions. Some of the reasons are lacking in the mechanism and guidance to analyse this new format of data. Thus, the aim of this study is to evaluate how the body of BSD can be mined, analysed and applied in the context of local government in the UK. The objective is to develop a Big Social Data Analytics (BSDA) model that can be applied in the case of local government. Data generated from social media over a year were collected, collated and analysed using a range of social media analytics and network analysis tools and techniques. The final BSDA model was applied to a local council case to evaluate its impact in real practice. This study allows to better understand the methods of analysing the BSD in the public sector and extend the literature related to e-government, social media, and social network theory / Universiti Utara Malaysia