Scalable System for Opinion Mining on Twitter Data. Dynamic Visualization for Data Related to Refugees’ Crisis and to Terrorist Attacks

Social networks such as Twitter or Facebook grew rapidly in popularity, and users use them to share opinions about topics of interest, to be part of the community or to post messages that are available everywhere. This paper presents a system created in order to process streamed data taken from Twitter and classify it into positive, negative or neutral. The results of these processing’s can be visualized in a suggestive manner on Google Maps, users can select the language of the tweets, can group tweets that present the same news and can even display a dynamic evolution of the news in terms of its appearance. With all this amount of information it is very opportune to do some data analysis to detect different types of events (and their locations) that happen worldwide, especially at the time when this data represents information related to refugee crisis or signals terrorist attacks

Evaluating User Image Tagging Credibility

International audienceWhen looking for information on the Web, the credibility of the source plays an important role in the information seeking experience. While data source credibility has been thoroughly studied for Web pages or blogs, the investigation of source credibility in image retrieval tasks is an emerging topic. In this paper, we first propose a novel dataset for evaluating the tagging credibility of Flickr users built with the aim of covering a large variety of topics. We present the motivation behind the need for such a dataset, the methodology used for its creation and detail important statistics on the number of users, images and rater agreement scores. Next, we define both a supervised learning task in which we group the users in 5 credibility classes and a credible user retrieval problem. Besides a couple of credibility features described in previous works, we propose a novel set of credibility estimators, with an emphasis on text based descriptors. Finally, we prove the usefulness of our evaluation dataset and justify the performances of the proposed credibility descriptors by showing promising results for both of the proposed tasks