287 research outputs found
Information spreading during emergencies and anomalous events
The most critical time for information to spread is in the aftermath of a
serious emergency, crisis, or disaster. Individuals affected by such situations
can now turn to an array of communication channels, from mobile phone calls and
text messages to social media posts, when alerting social ties. These channels
drastically improve the speed of information in a time-sensitive event, and
provide extant records of human dynamics during and afterward the event.
Retrospective analysis of such anomalous events provides researchers with a
class of "found experiments" that may be used to better understand social
spreading. In this chapter, we study information spreading due to a number of
emergency events, including the Boston Marathon Bombing and a plane crash at a
western European airport. We also contrast the different information which may
be gleaned by social media data compared with mobile phone data and we estimate
the rate of anomalous events in a mobile phone dataset using a proposed anomaly
detection method.Comment: 19 pages, 11 figure
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Tracing the German Centennial Flood in the Stream of Tweets: First Lessons Learned
Social microblogging services such as Twitter result in massive streams of georeferenced messages and geolocated status updates. This real-time source of information is invaluable for many application areas, in particular for disaster detection and response scenarios. Consequently, a considerable number of works has dealt with issues of their acquisition, analysis and visualization. Most of these works not only assume an appropriate percentage of georeferenced messages that allows for detecting relevant events for a specific region and time frame, but also that these geolocations are reasonably correct in representing places and times of the underlying spatio-temporal situation. In this paper, we review these two key assumption based on the results of applying a visual analytics approach to a dataset of georeferenced Tweets from Germany over eight months witnessing several large-scale flooding situations throughout the country. Our results con rm the potential of Twitter as a distributed 'social sensor' but at the same time highlight some caveats in interpreting immediate results. To overcome these limits we explore incorporating evidence from other data sources including further social media and mobile phone network metrics to detect, confirm and refine events with respect to location and time. We summarize the lessons learned from our initial analysis by proposing recommendations and outline possible future work directions
Cashtag piggybacking: uncovering spam and bot activity in stock microblogs on Twitter
Microblogs are increasingly exploited for predicting prices and traded
volumes of stocks in financial markets. However, it has been demonstrated that
much of the content shared in microblogging platforms is created and publicized
by bots and spammers. Yet, the presence (or lack thereof) and the impact of
fake stock microblogs has never systematically been investigated before. Here,
we study 9M tweets related to stocks of the 5 main financial markets in the US.
By comparing tweets with financial data from Google Finance, we highlight
important characteristics of Twitter stock microblogs. More importantly, we
uncover a malicious practice - referred to as cashtag piggybacking -
perpetrated by coordinated groups of bots and likely aimed at promoting
low-value stocks by exploiting the popularity of high-value ones. Among the
findings of our study is that as much as 71% of the authors of suspicious
financial tweets are classified as bots by a state-of-the-art spambot detection
algorithm. Furthermore, 37% of them were suspended by Twitter a few months
after our investigation. Our results call for the adoption of spam and bot
detection techniques in all studies and applications that exploit
user-generated content for predicting the stock market
Building a Test Collection for Significant-Event Detection in Arabic Tweets
With the increasing popularity of microblogging services like Twitter, researchers discov-
ered a rich medium for tackling real-life problems like event detection. However, event
detection in Twitter is often obstructed by the lack of public evaluation mechanisms
such as test collections (set of tweets, labels, and queries to measure the eectiveness of
an information retrieval system). The problem is more evident when non-English lan-
guages, e.g., Arabic, are concerned. With the recent surge of signicant events in the
Arab world, news agencies and decision makers rely on Twitters microblogging service to
obtain recent information on events. In this thesis, we address the problem of building a
test collection of Arabic tweets (named EveTAR) for the task of event detection.
To build EveTAR, we rst adopted an adequate denition of an event, which is a
signicant occurrence that takes place at a certain time. An occurrence is signicant if
there are news articles about it. We collected Arabic tweets using Twitter's streaming
API. Then, we identied a set of events from the Arabic data collection using Wikipedias
current events portal. Corresponding tweets were extracted by querying the Arabic data
collection with a set of manually-constructed queries. To obtain relevance judgments for
those tweets, we leveraged CrowdFlower's crowdsourcing platform.
Over a period of 4 weeks, we crawled over 590M tweets, from which we identied 66
events that cover 8 dierent categories and gathered more than 134k relevance judgments.
Each event contains an average of 779 relevant tweets. Over all events, we got an average
Kappa of 0.6, which is a substantially acceptable value. EveTAR was used to evalu-
ate three state-of-the-art event detection algorithms. The best performing algorithms
achieved 0.60 in F1 measure and 0.80 in both precision and recall. We plan to make
our test collection available for research, including events description, manually-crafted
queries to extract potentially-relevant tweets, and all judgments per tweet. EveTAR is
the rst Arabic test collection built from scratch for the task of event detection. Addi-
tionally, we show in our experiments that it supports other tasks like ad-hoc search
Event Detection from Social Media Stream: Methods, Datasets and Opportunities
Social media streams contain large and diverse amount of information, ranging
from daily-life stories to the latest global and local events and news.
Twitter, especially, allows a fast spread of events happening real time, and
enables individuals and organizations to stay informed of the events happening
now. Event detection from social media data poses different challenges from
traditional text and is a research area that has attracted much attention in
recent years. In this paper, we survey a wide range of event detection methods
for Twitter data stream, helping readers understand the recent development in
this area. We present the datasets available to the public. Furthermore, a few
research opportunitiesComment: 8 page
What’s Happening Around the World? A Survey and Framework on Event Detection Techniques on Twitter
© 2019, Springer Nature B.V. In the last few years, Twitter has become a popular platform for sharing opinions, experiences, news, and views in real-time. Twitter presents an interesting opportunity for detecting events happening around the world. The content (tweets) published on Twitter are short and pose diverse challenges for detecting and interpreting event-related information. This article provides insights into ongoing research and helps in understanding recent research trends and techniques used for event detection using Twitter data. We classify techniques and methodologies according to event types, orientation of content, event detection tasks, their evaluation, and common practices. We highlight the limitations of existing techniques and accordingly propose solutions to address the shortcomings. We propose a framework called EDoT based on the research trends, common practices, and techniques used for detecting events on Twitter. EDoT can serve as a guideline for developing event detection methods, especially for researchers who are new in this area. We also describe and compare data collection techniques, the effectiveness and shortcomings of various Twitter and non-Twitter-based features, and discuss various evaluation measures and benchmarking methodologies. Finally, we discuss the trends, limitations, and future directions for detecting events on Twitter
Can we predict a riot? Disruptive event detection using Twitter
In recent years, there has been increased interest in real-world event detection using publicly accessible data made available through Internet technology such as Twitter, Facebook, and YouTube. In these highly interactive systems, the general public are able to post real-time reactions to “real world” events, thereby acting as social sensors of terrestrial activity. Automatically detecting and categorizing events, particularly small-scale incidents, using streamed data is a non-trivial task but would be of high value to public safety organisations such as local police, who need to respond accordingly. To address this challenge, we present an end-to-end integrated event detection framework that comprises five main components: data collection, pre-processing, classification, online clustering, and summarization. The integration between classification and clustering enables events to be detected, as well as related smaller-scale “disruptive events,” smaller incidents that threaten social safety and security or could disrupt social order. We present an evaluation of the effectiveness of detecting events using a variety of features derived from Twitter posts, namely temporal, spatial, and textual content. We evaluate our framework on a large-scale, real-world dataset from Twitter. Furthermore, we apply our event detection system to a large corpus of tweets posted during the August 2011 riots in England. We use ground-truth data based on intelligence gathered by the London Metropolitan Police Service, which provides a record of actual terrestrial events and incidents during the riots, and show that our system can perform as well as terrestrial sources, and even better in some cases
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