457 research outputs found
Seminar Users in the Arabic Twitter Sphere
We introduce the notion of "seminar users", who are social media users
engaged in propaganda in support of a political entity. We develop a framework
that can identify such users with 84.4% precision and 76.1% recall. While our
dataset is from the Arab region, omitting language-specific features has only a
minor impact on classification performance, and thus, our approach could work
for detecting seminar users in other parts of the world and in other languages.
We further explored a controversial political topic to observe the prevalence
and potential potency of such users. In our case study, we found that 25% of
the users engaged in the topic are in fact seminar users and their tweets make
nearly a third of the on-topic tweets. Moreover, they are often successful in
affecting mainstream discourse with coordinated hashtag campaigns.Comment: to appear in SocInfo 201
Temporal Information Models for Real-Time Microblog Search
Real-time search in Twitter and other social media services is often biased
towards the most recent results due to the “in the moment” nature of topic
trends and their ephemeral relevance to users and media in general. However,
“in the moment”, it is often difficult to look at all emerging topics and single-out
the important ones from the rest of the social media chatter. This thesis proposes
to leverage on external sources to estimate the duration and burstiness of live
Twitter topics. It extends preliminary research where itwas shown that temporal
re-ranking using external sources could indeed improve the accuracy of results.
To further explore this topic we pursued three significant novel approaches: (1)
multi-source information analysis that explores behavioral dynamics of users,
such as Wikipedia live edits and page view streams, to detect topic trends
and estimate the topic interest over time; (2) efficient methods for federated
query expansion towards the improvement of query meaning; and (3) exploiting
multiple sources towards the detection of temporal query intent. It differs from
past approaches in the sense that it will work over real-time queries, leveraging
on live user-generated content. This approach contrasts with previous methods
that require an offline preprocessing step
Fostering Freedom Online: The Role of Internet Intermediaries
“Fostering Freedom Online: the Role of Internet Intermediaries” is the title of a new title in the UNESCO Internet freedom series. With the rise of Internet intermediaries that play a mediating role on the internet between authors of content and audiences, UNESCO took a joint initiative, with the Open Society Foundations, the Internet Society, and Center for Global Communication Studies at the University of Pennsylvania’s Annenberg School for Communication, to examine this recent historical phenomenon and how it impacts on freedom of expression and associated fundamental rights such as privacy.
The case study research, collaboratively delivered by 16 international researchers led by Ms Rebecca MacKinnon and Mr Allon Bar, as well as 14 members of International Advisory Committee, covers of three categories of intermediaries: Internet Service Providers (fixed line and mobile) such as Vodafone (UK, Germany, Egypt), Vivo/Telefônica Brasil (Brazil), Bharti Airtel (India, Kenya), Safaricom (Kenya), Search Engines such as Google (USA, EU, India, China, Russia), Baidu (China), Yandex (Russia) and Social Networking Platforms such as Facebook (USA, Germany, India, Brazil, Egypt), Twitter (USA, Kenya), Weibo (China), iWiW (Hungary).
The research showed that internet intermediaries are heavily influenced by the legal and policy environments of states, but they do have leeway over many areas of policy and practice affecting online expression and privacy. The findings also highlighted the challenge where many state policies, laws, and regulations are – to varying degrees – poorly aligned with the duty to promote and protect intermediaries’ respect for freedom of expression. It is a resource which enables the assessment of Internet intermediaries’ decisions on freedom of expression, by ensuring that any limitations are consistent with international standards
THE SURVIVAL AND DEVELOPMENT OF CHINESE NEW MEDIA BUSINESS: AMONG STATE, MARKET, AND PUBLIC
Master'sMASTER OF ART
Investigating Rumor Propagation with TwitterTrails
Social media have become part of modern news reporting, used by journalists
to spread information and find sources, or as a news source by individuals. The
quest for prominence and recognition on social media sites like Twitter can
sometimes eclipse accuracy and lead to the spread of false information. As a
way to study and react to this trend, we introduce {\sc TwitterTrails}, an
interactive, web-based tool ({\tt twittertrails.com}) that allows users to
investigate the origin and propagation characteristics of a rumor and its
refutation, if any, on Twitter. Visualizations of burst activity, propagation
timeline, retweet and co-retweeted networks help its users trace the spread of
a story. Within minutes {\sc TwitterTrails} will collect relevant tweets and
automatically answer several important questions regarding a rumor: its
originator, burst characteristics, propagators and main actors according to the
audience. In addition, it will compute and report the rumor's level of
visibility and, as an example of the power of crowdsourcing, the audience's
skepticism towards it which correlates with the rumor's credibility. We
envision {\sc TwitterTrails} as valuable tool for individual use, but we
especially for amateur and professional journalists investigating recent and
breaking stories. Further, its expanding collection of investigated rumors can
be used to answer questions regarding the amount and success of misinformation
on Twitter.Comment: 10 pages, 8 figures, under revie
Microblogging Temporal Summarization: Filtering Important Twitter Updates for Breaking News
While news stories are an important traditional medium to broadcast and consume news, microblogging has recently emerged as a place where people can dis- cuss, disseminate, collect or report information about news. However, the massive information in the microblogosphere makes it hard for readers to keep up with these real-time updates. This is especially a problem when it comes to breaking news, where people are more eager to know “what is happening”. Therefore, this dis- sertation is intended as an exploratory effort to investigate computational methods to augment human effort when monitoring the development of breaking news on a given topic from a microblog stream by extractively summarizing the updates in a timely manner.
More specifically, given an interest in a topic, either entered as a query or presented as an initial news report, a microblog temporal summarization system is proposed to filter microblog posts from a stream with three primary concerns: topical relevance, novelty, and salience. Considering the relatively high arrival rate of microblog streams, a cascade framework consisting of three stages is proposed to progressively reduce quantity of posts. For each step in the cascade, this dissertation studies methods that improve over current baselines.
In the relevance filtering stage, query and document expansion techniques are applied to mitigate sparsity and vocabulary mismatch issues. The use of word embedding as a basis for filtering is also explored, using unsupervised and supervised modeling to characterize lexical and semantic similarity. In the novelty filtering stage, several statistical ways of characterizing novelty are investigated and ensemble learning techniques are used to integrate results from these diverse techniques. These results are compared with a baseline clustering approach using both standard and delay-discounted measures. In the salience filtering stage, because of the real-time prediction requirement a method of learning verb phrase usage from past relevant news reports is used in conjunction with some standard measures for characterizing writing quality.
Following a Cranfield-like evaluation paradigm, this dissertation includes a se- ries of experiments to evaluate the proposed methods for each step, and for the end- to-end system. New microblog novelty and salience judgments are created, building on existing relevance judgments from the TREC Microblog track. The results point to future research directions at the intersection of social media, computational jour- nalism, information retrieval, automatic summarization, and machine learning
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