1,720,970 research outputs found
CONSENSUS-BASED CROWDSOURCING: TECHNIQUES AND APPLICATIONS
Full text linkCrowdsourcing solutions are receiving more and more attention in the recent literature about social computing and distributed problem solving. In general terms, crowdsourcing can be considered as a social-computing model aimed at fostering the autonomous formation and emergence of the so-called wisdom of the crowd. Quality assessment is a crucial issue for the effectiveness of crowdsourcing systems, both for what concerns task and worker management. Another aspect to be considered in crowdsourcing systems is about the kind of contributions workers can make. Usually, crowdsourcing approaches rely only on tasks where workers have to decide among a predefined set of possible solutions. On the other hand, tasks leaving the workers a higher level of freedom in producing their answer (e.g., free-hand drawing) are more difficult to be managed and verified. In the Thesis, we present the LiquidCrowd approach based on consensus and trustworthiness techniques for managing the xecution of collaborative tasks. By collaborative task, we refer to a task for which a factual answer is not possible/appropriate, or a task whose result depends on the personal perception/point-of-view of the worker. We introduce the notion of worker trustworthiness to denote the worker “reliability”, namely her/his capability to foster
the successful completion of tasks. Furthermore, we improve the conventional score-based mechanism by introducing the notion of award that is a bonus provided to those workers that contribute to reach the consensus within groups. This way, groups with certain trustworthiness requirements can be composed on-demand, to deal with complex tasks, like for example tasks where consensus has not been reached during the first execution. In LiquidCrowd , we define a democratic mechanism based on the notion of supermajority to enable the flexible specification of the expected degree of agreement required for obtaining the consensus within a worker group. In LiquidCrowd , three task typologies are provided: choice, where the worker is asked to choose the answer among a list of predefined options; range, where the worker is asked to provide a free-numeric answer; proposition, where the worker is asked to provide a free text answer.
To evaluate the quality of the produced results obtained through LiquidCrowd consensus techniques, we perform a testing against the SQUARE crowdsourcing benchmark. Furthermore, to evaluate the capability of LiquidCrowd to effectively support a real problem, real case studies about web data classification have been selected
Predictors Of Victimization Across Direct Bullying, Indirect Bullying and Cyberbullying
No full textOur study aims at testing the role of different predictors of victimization across the traditional and cyber forms of bullying in a sample of Italian adolescents. We’ll evaluate the influence of gender and age variables on the different forms of bullying investigated, as well as school clima, self-esteem and loneliness as reported by victims of traditional (direct/indirect) and cyberbullying (mobile/internet) in a sample of 1502 subjects from middle to high school (age range 12-16). Beside a questionnaire on new forms of bullying, measures for Self esteem and Loneliness were also provided. Logistic Regression Models show that although sex, school clima and Loneliness dimensions were significant predictors in all the three tested models, they showed different relations with the dependent variable.These results point out to different constellations of risk factors as a function of specific contexts in which the victims are involved
Urban information integration through smart city views
No full textObtaining a tailored and integrated information about events and points of interest of an urban area is becoming a major challenging issue for users like citizens and tourists that aim ateffectively enjoying the urban life initiatives. Inthis paper, we propose a comprehensive approach for urban information integration based on: i) similarity clusters, to aggregate web contents with different nature but similar topic; ii) smart city views, to package and deliver tailored cluster contents to the final users filtered according to user interest, geo-location, and time-based criteria, and iii) crowdsourced recommendations, to highlight the city view contents based on event freshness and popularity
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Urban information integration in MI-Search : results and future research activities
No full textIn this paper, we present the main achievements of the MI-Search project for “multi-web” information integration around topics relevant for urban users like for example city events and points of interest. In particular, we discuss the results of our experimental evaluation over a considered case study about the city of Milan as well as ongoing/future research activities in the framework of MI-Search
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Combining crowd consensus and user trustworthiness for managing collective tasks
No full textIn this paper, we present the LiquidCrowd methodological approach based on consensus and trustworthiness techniques for managing the execution of collective tasks. By collective task, we refer to a task in which the result depends on the consensus (i.e., degree of agreement) reached by the group of workers involved in the task execution. The more workers agree on a certain task answer, the more this answer is valid/accepted as a committed result for the task. In the paper, we provide crowdsourcing techniques for managing collective tasks based on the notion of supermajority to verify an expected degree of consensus/agreement required for considering a task as successfully completed. Moreover, we define trustworthiness techniques to measure the worker reliability/expertise in collective task execution in order to tailor the composition of a group by involving workers that are more able to express a sharable answer where needed. A case study of a collective task related to web-resource labeling is illustrated and evaluation results of the LiquidCrowd methodological approach are finally discussed
Multi-Web, event-centric urban information integration
No full textIn this paper, we present the MI-Search approach for enabling urban users to perform event-centric surfing of a multiplicity of web contents. MI-Search aims at exploiting traditional web sites and spontaneous user comments/posts in an integrated way, by relying on web data extracted from different sources and systems about the events of a selected urban space. The notion of smart city view is introduced in the paper to enforce a tailored exploration of these web contents according to the personal user interests expressed as keywords, geo-location constraints, and user-agenda appointments
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