2,164 research outputs found
Adaptive Representations for Tracking Breaking News on Twitter
Twitter is often the most up-to-date source for finding and tracking breaking
news stories. Therefore, there is considerable interest in developing filters
for tweet streams in order to track and summarize stories. This is a
non-trivial text analytics task as tweets are short, and standard retrieval
methods often fail as stories evolve over time. In this paper we examine the
effectiveness of adaptive mechanisms for tracking and summarizing breaking news
stories. We evaluate the effectiveness of these mechanisms on a number of
recent news events for which manually curated timelines are available.
Assessments based on ROUGE metrics indicate that an adaptive approaches are
best suited for tracking evolving stories on Twitter.Comment: 8 Pag
EveTAR: Building a Large-Scale Multi-Task Test Collection over Arabic Tweets
This article introduces a new language-independent approach for creating a
large-scale high-quality test collection of tweets that supports multiple
information retrieval (IR) tasks without running a shared-task campaign. The
adopted approach (demonstrated over Arabic tweets) designs the collection
around significant (i.e., popular) events, which enables the development of
topics that represent frequent information needs of Twitter users for which
rich content exists. That inherently facilitates the support of multiple tasks
that generally revolve around events, namely event detection, ad-hoc search,
timeline generation, and real-time summarization. The key highlights of the
approach include diversifying the judgment pool via interactive search and
multiple manually-crafted queries per topic, collecting high-quality
annotations via crowd-workers for relevancy and in-house annotators for
novelty, filtering out low-agreement topics and inaccessible tweets, and
providing multiple subsets of the collection for better availability. Applying
our methodology on Arabic tweets resulted in EveTAR , the first
freely-available tweet test collection for multiple IR tasks. EveTAR includes a
crawl of 355M Arabic tweets and covers 50 significant events for which about
62K tweets were judged with substantial average inter-annotator agreement
(Kappa value of 0.71). We demonstrate the usability of EveTAR by evaluating
existing algorithms in the respective tasks. Results indicate that the new
collection can support reliable ranking of IR systems that is comparable to
similar TREC collections, while providing strong baseline results for future
studies over Arabic tweets
High-level feature detection from video in TRECVid: a 5-year retrospective of achievements
Successful and effective content-based access to digital
video requires fast, accurate and scalable methods to determine the video content automatically. A variety of contemporary approaches to this rely on text taken from speech within the video, or on matching one video frame against others using low-level characteristics like
colour, texture, or shapes, or on determining and matching objects appearing within the video. Possibly the most important technique, however, is one which determines the presence or absence of a high-level or semantic feature, within a video clip or shot. By utilizing dozens, hundreds or even thousands of such semantic features we can support many kinds of content-based video navigation. Critically however, this depends on being able to determine whether each feature is or is not present in a video clip.
The last 5 years have seen much progress in the development of techniques to determine the presence of semantic features within video. This progress can be tracked in the annual TRECVid benchmarking activity where dozens of research groups measure the effectiveness of their techniques on common data and using an open, metrics-based approach. In this chapter we summarise the work
done on the TRECVid high-level feature task, showing the
progress made year-on-year. This provides a fairly comprehensive statement on where the state-of-the-art is regarding this important task, not just for one research group or for one approach, but across the spectrum. We then use this past and on-going work as a basis for highlighting the trends that are emerging in this area, and the questions which remain to be addressed before we can
achieve large-scale, fast and reliable high-level feature detection on video
combining multimodal external resources for event-based news video retrieval and question answering
Ph.DDOCTOR OF PHILOSOPH
Filtering News from Document Streams: Evaluation Aspects and Modeled Stream Utility
Events like hurricanes, earthquakes,
or accidents can impact a large number of people. Not only are people in the
immediate vicinity of the event affected, but concerns about their well-being are
shared by the local government and well-wishers across the world.
The latest information about news events
could be of use to government and aid agencies in order to make informed decisions on
providing necessary support, security and relief. The general public
avails of news updates via dedicated news feeds or broadcasts, and lately,
via social media services
like Facebook or Twitter.
Retrieving the latest information about newsworthy events from the world-wide web
is thus of importance to a large section of society.
As new content on a multitude of topics is continuously being published on the web,
specific event related information needs to be filtered from the resulting
stream of documents.
We present in this thesis, a user-centric evaluation measure for
evaluating systems that filter news related information from document streams.
Our proposed evaluation measure, Modeled Stream Utility (MSU), models
users accessing information from a stream of sentences
produced by a news update filtering system.
The user model allows for simulating a large number of users with different
characteristic stream browsing behavior. Through simulation,
MSU estimates the utility of a system for an
average user browsing a stream of sentences.
Our results show that system performance is sensitive to a user population's
stream browsing behavior and that
existing evaluation metrics correspond to very specific types of user behavior.
To evaluate systems that filter sentences from a document stream,
we need a set of judged sentences. This judged set is
a subset of all the sentences returned by all systems, and is
typically constructed by pooling
together the highest quality sentences,
as determined by respective system assigned scores for each sentence.
Sentences in the pool are manually assessed and
the resulting set of judged sentences is then used to compute system performance metrics.
In this thesis, we investigate the effect of including duplicates of
judged sentences, into the judged set, on system performance evaluation. We also develop an
alternative pooling methodology, that given the MSU user model,
selects sentences for pooling based on the probability of a sentences being read by
modeled users.
Our research lays the foundation for interesting future work for utilizing
user-models in different aspects of evaluation of stream filtering systems.
The MSU measure enables incorporation of different
user models. Furthermore, the applicability of MSU could be extended through
calibration based on user
behavior
A Survey on Uncovering trending stories from Twitter by extracting ground truth from datasets
Today’s online social networking services generates series of conversation that shows the all kinds of real-world events, however the large amount of data are available on social network. This data can be filtered for finding trending topics using standard natural language processing techniques. An Uncovering trending stories is therefore a building block is to extract and summarizes the information raised from social networking services, this building block is very useful to find trending stories and its initiator .There are verity of methods that improves quality of result. This paper explores about different Topic detection method for uncovering trending topics from twitter datasets, such as Document-Pivot methods, Feature-Pivot methods, Frequent Pattern Mining, Soft Frequent Pattern Mining and BNgram
- …