Representativeness and Diversity in Photos via Crowd-Sourced Media Analysis

In this paper we present a hybrid three steps mechanism for automated-human media analysis employed for selecting a small number of representative and diverse images in the context of a noisy set of images. The first step consists in the automatic retrieval from web of a large database of candidate images. In the second step, a proposed image analysis method is employed with the goal of diminishing the time, pay and cognitive load and implicitly people’s work. This is done by automatically selecting a set of potentially relevant and diverse images. Considering the semantic gap between low-level features and high-level semantics in images, the last step is necessary and consists in images being annotated and assessed by the crowd. The aim is to evaluate the level of representativeness and diversity of the selected set of images and providing images of highest quality. The method was validated in the context of the retrieval of images with monuments and using more than 30,000 images retrieved from various social image search platforms

InterPoll: Crowd-Sourced Internet Polls

Crowd-sourcing is increasingly being used to provide answers to online polls and surveys. However, existing systems, while taking care of the mechanics of attracting crowd workers, poll building, and payment, provide little to help the survey-maker or pollster in obtaining statistically significant results devoid of even the obvious selection biases. This paper proposes InterPoll, a platform for programming of crowd-sourced polls. Pollsters express polls as embedded LINQ queries and the runtime correctly reasons about uncertainty in those polls, only polling as many people as required to meet statistical guarantees. To optimize the cost of polls, InterPoll performs query optimization, as well as bias correction and power analysis. The goal of InterPoll is to provide a system that can be reliably used for research into marketing, social and political science questions. This paper highlights some of the existing challenges and how InterPoll is designed to address most of them. In this paper we summarize some of the work we have already done and give an outline for future work

Spatial and Temporal Sentiment Analysis of Twitter data

The public have used Twitter world wide for expressing opinions. This study focuses on spatio-temporal variation of georeferenced Tweets’ sentiment polarity, with a view to understanding how opinions evolve on Twitter over space and time and across communities of users. More specifically, the question this study tested is whether sentiment polarity on Twitter exhibits specific time-location patterns. The aim of the study is to investigate the spatial and temporal distribution of georeferenced Twitter sentiment polarity within the area of 1 km buffer around the Curtin Bentley campus boundary in Perth, Western Australia. Tweets posted in campus were assigned into six spatial zones and four time zones. A sentiment analysis was then conducted for each zone using the sentiment analyser tool in the Starlight Visual Information System software. The Feature Manipulation Engine was employed to convert non-spatial files into spatial and temporal feature class. The spatial and temporal distribution of Twitter sentiment polarity patterns over space and time was mapped using Geographic Information Systems (GIS). Some interesting results were identified. For example, the highest percentage of positive Tweets occurred in the social science area, while science and engineering and dormitory areas had the highest percentage of negative postings. The number of negative Tweets increases in the library and science and engineering areas as the end of the semester approaches, reaching a peak around an exam period, while the percentage of negative Tweets drops at the end of the semester in the entertainment and sport and dormitory area. This study will provide some insights into understanding students and staff ’s sentiment variation on Twitter, which could be useful for university teaching and learning management

Taking the urban tourist activity pulse through digital footprints

An insight on urban tourism-related phenomena is provided in this study by analysing open and volunteered user generated content. A reference framework method is proposed and applied to an illustrative case study to meet a twofold objective: to identify Tourist Activity Centre – TAC – areas based on their functional character – sightseeing, shopping, eating and nightlife; and, to obtain an up-to-date fine-grain characterization of the most dynamic zones in an urban context. Instasights Heatmaps and data from Location Based Social Networks – Foursquare, Google Places, Twitter and Airbnb – were used to depict tourist urban activity. This reproducible method transcends Instasights generic visualization of popular areas by exploiting the benefits of overlapping LBSN data sources. This method facilitates a granular analysis of tourism-related places of interest and makes headway in bridging the gap between traditional approaches and user preferences, revealed through digital footprints, for urban analysis. The results indicate the potential of this method as a complementary tool for urban planning decision-making.This research was funded by the Vice-rectorate of Research and Knowledge Transfer of the University of Alicante, in the context of the Program for the promotion of R+D+I. This work was developed within the scope of the research project entitled: "[LIVELYCITY] Interdisciplinary methods for the study of the city through geolocated social networks", reference GRE18-19

The Media Work of Syrian Diaspora Activists : Brokering Between the Protest and Mainstream Media

The role of Syrian diaspora activists has been identified as key to both supporting and shaping the world’s image of the Syrian uprising. This article examines the multifaceted media work of Syrian diaspora activists, conceptualized as “cultural brokerage” in a global and national setting. Based on personal interviews with activists in exile in five countries, this study identifies and analyzes three main aspects of brokerage: (a) linking the voices of protesters inside the country to the outside world, (b) managing messages to bridge the gap between social media and mainstream media, and (c) collaborating with professional journalists and translating messages to fit the contexts and understandings of foreign publics.Peer reviewe

European Handbook of Crowdsourced Geographic Information

"This book focuses on the study of the remarkable new source of geographic information that has become available in the form of user-generated content accessible over the Internet through mobile and Web applications. The exploitation, integration and application of these sources, termed volunteered geographic information (VGI) or crowdsourced geographic information (CGI), offer scientists an unprecedented opportunity to conduct research on a variety of topics at multiple scales and for diversified objectives. The Handbook is organized in five parts, addressing the fundamental questions: What motivates citizens to provide such information in the public domain, and what factors govern/predict its validity?What methods might be used to validate such information? Can VGI be framed within the larger domain of sensor networks, in which inert and static sensors are replaced or combined by intelligent and mobile humans equipped with sensing devices? What limitations are imposed on VGI by differential access to broadband Internet, mobile phones, and other communication technologies, and by concerns over privacy? How do VGI and crowdsourcing enable innovation applications to benefit human society? Chapters examine how crowdsourcing techniques and methods, and the VGI phenomenon, have motivated a multidisciplinary research community to identify both fields of applications and quality criteria depending on the use of VGI. Besides harvesting tools and storage of these data, research has paid remarkable attention to these information resources, in an age when information and participation is one of the most important drivers of development. The collection opens questions and points to new research directions in addition to the findings that each of the authors demonstrates. Despite rapid progress in VGI research, this Handbook also shows that there are technical, social, political and methodological challenges that require further studies and research.

Plural relational green space values for whom, when, and where? - A social media approach

Unidad de excelencia María de Maeztu CEX2019-000940-MThe values people ascribe to their interactions with and within the environment are essential to inform justice and sustainability transformations. The development of many of these values unfolds through enjoying so-called cultural ecosystem services (CES) such as outdoor recreation, landscape aesthetics or environmental education. A growing body of literature is improving the assessment of the multiple ways that people value human and non-human relations arising when enjoying CES. Yet, the geo-temporal-demographic patterns of values distribution and the lessons that can be derived are to be consistently analysed within this relational framework. Building on a visual and textual content analysis of social media (SM) data geotagged in a peri-urban park of Barcelona, Spain, this research explores the potential of analysing the associated metadata (such as geotag, timestamp and social media users' demographics - i.e., performed gender and residency) in order to develop a better understanding of the linkages between people's values and the situated context of their construction. Our results show trends in relational CES values distribution along and between the analysed spatial, temporal, and demographic dimensions. In particular, despite there being a multiplicity of values revealed across the whole case-study area, to enjoy contemplative CES, such as spiritual or cognitive value, people need to move away from highly frequented areas and prefer specific times of the day, respectively evening or afternoon. Locals show a higher preference to visit the park on weekends compared to non-locals, while women-performing users show a significantly higher drop in their CES benefits uptake compared to men-performing users at night. In addition to providing novel and fine-grained information for transformative practices toward justice and sustainability, this study highlights the importance of complementing CES studies employing SM with metadata analysis to improve our understanding of the relationship between the real and the more-than-real