Of course we share! Testing Assumptions about Social Tagging Systems

Social tagging systems have established themselves as an important part in today's web and have attracted the interest from our research community in a variety of investigations. The overall vision of our community is that simply through interactions with the system, i.e., through tagging and sharing of resources, users would contribute to building useful semantic structures as well as resource indexes using uncontrolled vocabulary not only due to the easy-to-use mechanics. Henceforth, a variety of assumptions about social tagging systems have emerged, yet testing them has been difficult due to the absence of suitable data. In this work we thoroughly investigate three available assumptions - e.g., is a tagging system really social? - by examining live log data gathered from the real-world public social tagging system BibSonomy. Our empirical results indicate that while some of these assumptions hold to a certain extent, other assumptions need to be reflected and viewed in a very critical light. Our observations have implications for the design of future search and other algorithms to better reflect the actual user behavior

Open source data mining infrastructure for exploring and analysing OpenStreetMap

OpenStreetMap and other Volunteered Geographic Information datasets have been explored in the last years, with the aim of understanding how their meaning is rendered, of assessing their quality, and of understanding the community-driven process that creates and maintains the data. Research mostly focuses either on the data themselves while ignoring the social processes behind, or solely discusses the community-driven process without making sense of the data at a larger scale. A holistic understanding that takes these and other aspects into account is, however, seldom gained. This article describes a server infrastructure to collect and process data about different aspects of OpenStreetMap. The resulting data are offered publicly in a common container format, which fosters the simultaneous examination of different aspects with the aim of gaining a more holistic view and facilitates the results’ reproducibility. As an example of such uses, we discuss the project OSMvis. This project offers a number of visualizations, which use the datasets produced by the server infrastructure to explore and visually analyse different aspects of OpenStreetMap. While the server infrastructure can serve as a blueprint for similar endeavours, the created datasets are of interest themselves too

Confirmation Bias in Information Search with Social Tags

Confirmation bias is the tendency of information searchers to select and evaluate information that supports pre-existing attitudes favourably. The current dissertation investigates whether confirmation bias affects health-related search in online environments, where users share content and social tag clouds are the navigation interface for searchers. I assumed that when individuals search health-related issues, they are motivated to find accurate information (accuracy motivation), in contrast to defending their self-concept (defense motivation). To determine what information is accurate, I expect that searchers attend to internal, individual evaluations (prior knowledge, prior attitudes, and attitude confidence), and external, collective cues (tag popularity and source credibility). Regarding the influence of individual evaluations, in studies 2 and 3, a linear influence of prior attitudes on the selection of blog posts (but not tags), and the evaluation of blog posts was found. In studies 2 and 3, I tested whether the influence of prior attitudes was moderated by confidence. I found that high confidence did affect the selection of blog posts but not tags in both studies, and confidence influenced the evaluation of tag-related blog posts. Regarding the influence of the collective cues, tag popularity was manipulated in studies 1 and 3, where I found a main effect of tag popularity on the selection of tags, blog posts, and evaluation of content, showing that tag size influenced confirmation bias in a moderate to strong way. In the student sample (study 2), I found that high credibility reduced the influence of prior attitudes on the selection of tags and consequently blog posts. However, using a representative sample (study 3), no influence of source credibility was found. With respect to the searchers’ evaluation of content, credibility had no influence in study 2, but in study 3, under high source credibility and low attitude confidence, searchers evaluated content more favourably when content was attitude consistent. In conclusion, the present dissertation shows that confirmation bias and individual evaluations guide information searchers in tag-based navigation, extending the literature which showed behaviour in social tagging environments follows semantic associations. The results are interesting for the construction of content aggregation or social tagging platforms, and practitioners who provide health-related online content. Practitioners and platform providers pay attention to their target audience, as this will either elicit accuracy or defense motivation. So, different strategies can be implemented when the aim is to reduce the influence of confirmation bias on information search behaviour.Der Bestätigungsfehler ist die Tendenz Informationen so auszuwählen und zu bewerten, dass bestehende Einstellungen verstärkt werden. In dieser Dissertation untersuche ich, ob der Bestätigungsfehler auch in Online-Umgebungen auftritt, wo Nutzer auf geteilte Inhalte über Social Tag Clouds zugreifen. Personen sollten bei der gesundheitsbezogenen Suche nicht dazu tendieren, dass sie ihr Selbstkonzept aufrechterhalten (Verteidigungsmotiv), sondern sie sollten Inhalte gemäß ihrer Korrektheit auswählen (Genauigkeitsmotiv). Um die Korrektheit der Inhalte einzuschätzen berücksichtigen Nutzer internale, individuelle Bewertungen (Vorwissen, Voreinstellungen, Einstellungsgewissheit), sowie externale, kollektive Reize (Tag Popularität, Glaubwürdigkeit). Dies ist eine bedeutsame Erweiterung zur Literatur Sozialer Tagging Systeme, die bisher ausschließlich den Einfluss semantischer Assoziationen im menschlichen Gedächtnis und den Einfluss aggregierter, kollektiver Assoziationen untersucht. In den Studien 2 und 3 zeigte sich ein linearer Einfluss von Voreinstellungen auf die Auswahl und Bewertung von Blogeinträgen. Hier testete ich auch, ob der Einfluss der Voreinstellungen durch Einstellungsgewissheit moderiert würde. Einstellungsgewissheit beeinflusste die Auswahl von Blogeinträgen und deren Bewertung. In den Studien 1 und 3 zeigte sich ein Effekt der Tag-Popularität auf die Auswahl von Tags, Blogeinträgen und die Bewertung von Inhalten. Außerdem zeigte sich in der Studierendenstichprobe (Studie 2), dass hohe Glaubwürdigkeit den Einfluss von Einstellungen auf die Navigation reduzierte. In Studie 3, mit einer repräsentativen Stichprobe, wurde dies jedoch nicht gefunden. In Bezug auf die Bewertung von Inhalten hatte die Glaubwürdigkeit keinen Einfluss in Studie 2, aber in Studie 3 bewertete die repräsentative Stichprobe von Suchenden bei hoher Glaubwürdigkeit und gleichzeitig geringer Einstellungsgewissheit Inhalte günstiger, wenn sie einstellungs-kongruent waren. Somit zeigte sich, dass Informationssuchende in der Tag-basierten Navigation dem Bestätigungsfehler unterliegen. Dies ist eine bedeutende Erweiterung zur Literatur, die gezeigt hat, dass Informationssuche und Bewertung in Social-Tagging-Umgebungen semantischen Assoziationen folgen. Die vorliegenden Ergebnisse zeigen interessante Implikationen für die Gestaltung von Social-Tagging Plattformen. So ist es beispielsweise wichtig, die Zielgruppe zu berücksichtigen, da sie bestimmt, ob Suchende im gesundheitsbezogenen Kontext durch Genauigkeits- oder Verteidigungsmotive geleitet sind

Semantic Interaction in Web-based Retrieval Systems : Adopting Semantic Web Technologies and Social Networking Paradigms for Interacting with Semi-structured Web Data

Existing web retrieval models for exploration and interaction with web data do not take into account semantic information, nor do they allow for new forms of interaction by employing meaningful interaction and navigation metaphors in 2D/3D. This thesis researches means for introducing a semantic dimension into the search and exploration process of web content to enable a significantly positive user experience. Therefore, an inherently dynamic view beyond single concepts and models from semantic information processing, information extraction and human-machine interaction is adopted. Essential tasks for semantic interaction such as semantic annotation, semantic mediation and semantic human-computer interaction were identified and elaborated for two general application scenarios in web retrieval: Web-based Question Answering in a knowledge-based dialogue system and semantic exploration of information spaces in 2D/3D

Upper Tag Ontology (UTO) For Integrating Social Tagging Data

Data integration and mediation have become central concerns of information technology over the past few decades. With the advent of the Web and the rapid increases in the amount of data and the number of Web documents and users, researchers have focused on enhancing the interoperability of data through the development of metadata schemes. Other researchers have looked to the wealth of metadata generated by bookmarking sites on the Social Web. While several existing ontologies have capitalized on the semantics of metadata created by tagging activities, the Upper Tag Ontology (UTO) emphasizes the structure of tagging activities to facilitate modeling of tagging data and the integration of data from different bookmarking sites as well as the alignment of tagging ontologies. UTO is described and its utility in modeling, harvesting, integrating, searching, and analyzing data is demonstrated with metadata harvested from three major social tagging systems (Delicious, Flickr, and YouTube)

Casual Information Visualization on Exploring Spatiotemporal Data

The goal of this thesis is to study how the diverse data on the Web which are familiar to everyone can be visualized, and with a special consideration on their spatial and temporal information. We introduce novel approaches and visualization techniques dealing with different types of data contents: interactively browsing large amount of tags linking with geospace and time, navigating and locating spatiotemporal photos or videos in collections, and especially, providing visual supports for the exploration of diverse Web contents on arbitrary webpages in terms of augmented Web browsing

From Keyword Search to Exploration: How Result Visualization Aids Discovery on the Web

A key to the Web's success is the power of search. The elegant way in which search results are returned is usually remarkably effective. However, for exploratory search in which users need to learn, discover, and understand novel or complex topics, there is substantial room for improvement. Human computer interaction researchers and web browser designers have developed novel strategies to improve Web search by enabling users to conveniently visualize, manipulate, and organize their Web search results. This monograph offers fresh ways to think about search-related cognitive processes and describes innovative design approaches to browsers and related tools. For instance, while key word search presents users with results for specific information (e.g., what is the capitol of Peru), other methods may let users see and explore the contexts of their requests for information (related or previous work, conflicting information), or the properties that associate groups of information assets (group legal decisions by lead attorney). We also consider the both traditional and novel ways in which these strategies have been evaluated. From our review of cognitive processes, browser design, and evaluations, we reflect on the future opportunities and new paradigms for exploring and interacting with Web search results

How to tell stories using visualization: strategies towards narrative visualization

Os benefícios da utilização das narrativas são desde há muito conhecidos e o seu potencial para simplificar conceitos, transmitir valores culturais e experiências, criar ligações emocionais e capacidade para ajudar a reter a informação tem sido explorado em diferentes áreas. As narrativas não são só a principal forma como as pessoas obtêm o sentido do mundo, mas também a forma mais fácil que encontrámos para partilhar informações complexas. Devido ao seu potencial, as narrativas foram recentemente abordadas na área da Visualização de Informação e do Conhecimento, muitas vezes apelidada de Visualização Narrativa. Esta questão é particularmente importante para os media, uma das áreas que tem impulsionado a investigação em Visualização Narrativa. A necessidade de incorporar histórias nas visualizações surge da necessidade de partilhar dados complexos de um modo envolvente. Hoje em dia somos confrontados com a elevada quantidade de informação disponível, um desafio difícil de resolver. Os avanços da tecnologia permitiram ir além das formas tradicionais de narrativa e de representação de dados, dando-nos meios mais atraentes e sofisticados para contar histórias. Nesta tese, exploro os benefícios da introdução de narrativas nas visualizações. Adicionalmente também exploro formas de combinar histórias com a visualizações e métodos eficientes para representar e dar sentido aos dados de uma forma que permite que as pessoas se relacionem com a informação. Esta investigação está bastante próxima da área do jornalismo, no entanto estas técnicas podem ser aplicadas em diferente áreas (educação, visualização científica, etc.). Para explorar ainda mais este tema foi adotada um avaliação que utiliza diferentes metodologias como a tipologia, vários casos de estudo, um estudo com grupos de foco, e ainda estudos de design e análise de técnicas.The benefits of storytelling are long-known and its potential to simplify concepts, convey cultural values and experiences, create emotional connection, and capacity to help retain information has been explored in di erent areas, such as journalism, education, marketing, and others. Narratives not only have been the main way people make sense of the world, but also the easiest way humans found out to share complex information. Due to its potential narratives have also recently been approached in the area of Information and Knowledge Visualization, several times being referred to as Narrative Visualization. This matter is also particularly important for news media, one of the areas that has been pushing the research on Narrative Visualization. The necessity to incorporate storytelling in visualizations arises from the need to share complex data in a way that is engaging. Nowadays we also have the challenge of the high amount of information available, which can be hard to cope with. Advances in technology have enabled us to go beyond the traditional forms of storytelling and representing data, giving us more attractive and sophisticated means to tell stories. In this dissertation, I explore the benefits of infusing visualizations with narratives. In addition I also present ways of combining storytelling with visualization and e cient methods to represent and make sense of data in a way that allows people to relate with the information. This research is closely related to journalism, but these techniques can be applied to completely di erent areas (education, scientific visualization, etc.). To further explore this topic a mixedmethod evaluation that consists of a typology, several case studies and a focus group study was chosen, as well as design studies and techniques review. This dissertation is intended to contribute to the evolving understanding of the field of narrative visualization

Social software for music

Tese de mestrado integrado. Engenharia Informática e Computação. Faculdade de Engenharia. Universidade do Porto. 200

Exploratory Browsing

In recent years the digital media has influenced many areas of our life. The transition from analogue to digital has substantially changed our ways of dealing with media collections. Today‟s interfaces for managing digital media mainly offer fixed linear models corresponding to the underlying technical concepts (folders, events, albums, etc.), or the metaphors borrowed from the analogue counterparts (e.g., stacks, film rolls). However, people‟s mental interpretations of their media collections often go beyond the scope of linear scan. Besides explicit search with specific goals, current interfaces can not sufficiently support the explorative and often non-linear behavior. This dissertation presents an exploration of interface design to enhance the browsing experience with media collections. The main outcome of this thesis is a new model of Exploratory Browsing to guide the design of interfaces to support the full range of browsing activities, especially the Exploratory Browsing. We define Exploratory Browsing as the behavior when the user is uncertain about her or his targets and needs to discover areas of interest (exploratory), in which she or he can explore in detail and possibly find some acceptable items (browsing). According to the browsing objectives, we group browsing activities into three categories: Search Browsing, General Purpose Browsing and Serendipitous Browsing. In the context of this thesis, Exploratory Browsing refers to the latter two browsing activities, which goes beyond explicit search with specific objectives. We systematically explore the design space of interfaces to support the Exploratory Browsing experience. Applying the methodology of User-Centered Design, we develop eight prototypes, covering two main usage contexts of browsing with personal collections and in online communities. The main studied media types are photographs and music. The main contribution of this thesis lies in deepening the understanding of how people‟s exploratory behavior has an impact on the interface design. This thesis contributes to the field of interface design for media collections in several aspects. With the goal to inform the interface design to support the Exploratory Browsing experience with media collections, we present a model of Exploratory Browsing, covering the full range of exploratory activities around media collections. We investigate this model in different usage contexts and develop eight prototypes. The substantial implications gathered during the development and evaluation of these prototypes inform the further refinement of our model: We uncover the underlying transitional relations between browsing activities and discover several stimulators to encourage a fluid and effective activity transition. Based on this model, we propose a catalogue of general interface characteristics, and employ this catalogue as criteria to analyze the effectiveness of our prototypes. We also present several general suggestions for designing interfaces for media collections