social media news mining and automatic content analysis of news
TRANSCRIPT
Social Media News Mining &Automatic Content Analysisof NewsCarlos Castillo – Qatar Computing Research Institute
Nov 14th, 2013
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Carlos Castillo – [email protected]://www.chato.cl/research/
Outline
• Social media around news1. Predictive analytics using social media2. Crowds and curators
• Automatic content analysis of news3. TV news via closed captions4. Online news in international media
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Carlos Castillo – [email protected]://www.chato.cl/research/
Communication scholarsvs. Computer scientists
• Media and communication scholars– Start from high-level questions
• Computer scientists– Start from low-level observations
• We need to find a middle ground– To a large extent, we are still not there– I am certainly still not there
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Carlos Castillo – [email protected]://www.chato.cl/research/
Collaborators• Gianmarco de Francisci Morales – Yahoo!• Mohammed El-Haddad – Al Jazeera• Sandra González-Bailón – University of Pennsylvania• Nasir Khan – Al Jazeera• Mounia Lalmas – Yahoo!• Janette Lehmann – Pompeu Fabra University & Yahoo!• Marcelo Mendoza – Yahoo!• Jürgen Pfeffer – CMU• Matt Stempeck – MIT Civic Media• Diego Sáez-Trumper – Pompeu Fabra University• Ethan Zuckerman – MIT Civic Media
Predictive analytics using social mediaCarlos Castillo, Mohammed El-Haddad, Jürgen Pfeffer and Matt StempeckCharacterizing the Life Cycle of Online News Stories Using Social Media ReactionsTo appear in Proc. of Computer Supported Collaborative Work and Social Media.Baltimore, MD, USA. February 2014.
See also: demo at http://fast.qcri.org/
Topic 1 of 4
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Carlos Castillo – [email protected]://www.chato.cl/research/
Usage analysis (in news) online
• Aikat (1998)– Bursts, short dwell times, weekday != weekend
• Crane and Sornette (2008), Yang and Leskovec (2011), Lehmann et al. (2012)– Behavioral classes of attention online
• Lotan, Gaffney, and Meyer (SocialFlow, 2011)– Al Jazeera, BBC, CNN, The Economist, Fox News, NY
Times
• … and many others!
News examples In-Depth examples
● Dozens killed in India bus-crash blaze (Oct 30th, 2013)
● Kenyan army admits soldiers looted mall (Oct 30th, 2013)
● Sex selective abortions worry Azerbaijanis (Oct 29th, 2013)
● Time to put an end to Israel's don't ask-don't tell nuclear policy (Oct 18th, 2013)
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Carlos Castillo – [email protected]://www.chato.cl/research/
Average visitation/sharing profiles
News In-Depth
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Carlos Castillo – [email protected]://www.chato.cl/research/
Types of news visitation profiles (12 h)
Decreasing (78%)
Steady (9%)
Increasing (3%)
Rebounding (10%)
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Carlos Castillo – [email protected]://www.chato.cl/research/
Prediction of visits
• Short-term traffic is to a large extent correlated with long-term traffic
• Social media signals are correlated with traffic and shelf-life
More reactions → more trafficMore discussion → longer shelf-life
• Can we predict 7 days after 30 minutes?
http://fast.qcri.org/
Predictions are updated as new information arrives. Predictive models are re-trained every 24 hours. Traffic to many (but not all) articles is easy to predict.
Don't remove over- achievers, promote under- achievers.
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Carlos Castillo – [email protected]://www.chato.cl/research/
Take-home messages
• Decrease, Stay or Increase. Rebound– Roughly 80:10:10 ratio in first 12 hours
• News vs In-Depth: different behavior– News pieces die out rapidly on the web– In-Depth pieces live longer
• Visit forecasting can help take more informed editorial decisions
News crowds and news curators in social mediaJanette Lehmann, Carlos Castillo, Mounia Lalmas and Ethan Zuckerman:Transient News Crowds in Social MediaIn Proc. of International Conference on Weblogs and Social Media.Cambridge, MA, USA, July 2013. See also: blog post.
Janette Lehmann, Carlos Castillo, Mounia Lalmas and Ethan Zuckerman:Finding News Curators in TwitterSocial News on the Web (SNOW) workshop.Rio de Janeiro, Brazil, May 2013. See also: blog post.
Topic 2 of 4
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Carlos Castillo – [email protected]://www.chato.cl/research/
Empirical results
• Experiment with articles in BBC and AJE• People who tweeted an article within 6 hours of
publication → news crowd– Follow the crowd for one week– Divide time in 12-hour slices
• Most crowds disperse rapidly– They tweeted once about the same thing– Now they tweet about different things
• Some crowds re-group later
Syria allows UN to step up food aid
French troops launch
ground combat
in Mali13 Jan 2013
13 Jan 2013
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Carlos Castillo – [email protected]://www.chato.cl/research/
How do we find the related ones?
• Machine-learning approach• Important attributes
– Text similarity to original story– Exclusivity of history to this crowd
• Finds 14% to 72% of related stories automatically (@ 2/3 precision)
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Carlos Castillo – [email protected]://www.chato.cl/research/
Focus on articles → focus on users
Twitter user Followers Tweets about ...
@RevolutionSyria 88,122 Syria
@KenanFreeSyria 13,388 Syria
@UP_food 703 Food
@KeriJSmith 8,838 Breaking news/top stories
@BreakingNews 5,662,866 Breaking news/top stories
Example: which users with a large number of followers tweeted
Syria allows UN to step up food aid (16 Jan 2013)
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Carlos Castillo – [email protected]://www.chato.cl/research/
News curators
• Think Andy Carvin @acarvin, who was a “distant witness” of the Arab Spring
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Carlos Castillo – [email protected]://www.chato.cl/research/
Do we have curators in Twitter?
Human Automatic
Topic-unfocus
ed
Topic-unfocused curatorDisseminating news articles about diverse topics, usually breaking news/top stories
@KeriJSmith
News aggregatorsCollecting news articles (e.g. from RSS feeds) and automatically post their corresponding headlines and URLs@BreakingNews
Topic-focused
Topic-focused curatorCollecting interesting information with a specific focus, usually a geographic region or a topic@KenanFreeSyria
Topic-focused aggregatorsDisseminating automatically news with topical focus
@UP_food, @RevolutionSyria
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Carlos Castillo – [email protected]://www.chato.cl/research/
Which users do we care about?
Human Automatic
Topic-focused
Topic-focused curatorCollecting interesting information with a specific focus, usually a geographic region or a topic@KenanFreeSyria
Topic-focused aggregatorsDisseminating automatically news with topical focus
@UP_food, @RevolutionSyria
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Carlos Castillo – [email protected]://www.chato.cl/research/
Manual annotation (200 users)
13%
8%
79%
Focused - Human
Focused - Auto
Unfocused
2%
3%
95%
Focused - Human
Focused - Auto
Unfocused
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Carlos Castillo – [email protected]://www.chato.cl/research/
Automatically finding curators
• Simple rules– UserFracURL >= 85%: automatic– UserSectionsQ >= 90%: unfocused
• Complex model (AUC > 0.90)– Random forest
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Carlos Castillo – [email protected]://www.chato.cl/research/
Take-home messages
• Twitter users quickly shift topics– But sometimes return to a topic
• There are excellent news curators in Twitter– Although many of them are automatic
• Automatic systems can help identify curators and follow-up news
Analysis of TV news viaclosed captionsCarlos Castillo, Gianmarco De Francisci Morales, Marcelo Mendoza, Nasir Khan:Says Who? Automatic Text-based Content Analysis of Television NewsWorkshop on Mining Unstructured Data Using NLP (UnstructureNLP).Burlington, CA, USA. October 2013.
Topic 3 of 4
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Carlos Castillo – [email protected]://www.chato.cl/research/
Acquiring closed captions
• We used data from Yahoo's IntoNow– 140 TV channels– 2MB/channel/day– Jan-Jun 2012
• Internet Archive: http://archive.org/details/tv
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Carlos Castillo – [email protected]://www.chato.cl/research/
Text pre-processing: input
[1339302660] WHAT MORE CAN YOU ASK FOR?
[1339302662] >> THIS IS WHAT NBA
[1339302663] BASKETBALL IS ABOUT
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Carlos Castillo – [email protected]://www.chato.cl/research/
Text pre-processing: output
What/WP more/JJR can/MD you/PRP ask/VB
for/IN ?/. This/DT is/VBZ what/WDT
NBA/NNP [entity: National_Basketball_
Association] basketball/NN is/VBZ
about/IN ./. [sentiment: 0.0]
Clusters by non-entity words
General news
Sport news
General + entertainment
Sports
Sports
General news
Sports
General + sports
Business + sports
Business + sports
Sorting by average sentiment
Mixed
Sports
Sentiment scores on TV captions go from neutral to positive.
Strong positive words are used more than strong negative words?
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Carlos Castillo – [email protected]://www.chato.cl/research/
Automatic TV ↔ online news matching
• Same pre-processing is done over articles on the Yahoo! News website
• Genre classification (general, sports, business, entertainment) by– Data from TV guide for closed captions– Section in Yahoo! News for web news
Coverage by prominence
TV networks with more resources can cover more stories.
Some prefer to cover only prominent ones, others want some niche content.
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Carlos Castillo – [email protected]://www.chato.cl/research/
Newsmakers
• By professional activity– Sentiments– Distributions
• In relationship to news providers
• Everybody is a (potential) entertainer
Distributions of mentions per person
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Carlos Castillo – [email protected]://www.chato.cl/research/
Take-home messages
• Closed captions are a goldmine of data for content analysis
• Automatic content analysis is feasible up to a certain extent– But we still need to learn to use it
• Reduce subjectivity when trying to answer some research questions
Biases in online news in international news mediaDiego Sáez-Trumper, Carlos Castillo and Mounia Lalmas:Social Media News Communities: Gatekeeping, Coverage, and Statement BiasIn Proc. of Conference on Information and Knowledge Management (short paper).Burlingame, CA, USA, October 2013.
Topic 4 of 4
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Carlos Castillo – [email protected]://www.chato.cl/research/
Selection bias
Coverage bias
Statement bias
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Carlos Castillo – [email protected]://www.chato.cl/research/
Goal: discover bias in news media
• 60+ news sources in English– BBC, CNN, Fox, Time, UPI, Herald Sun, Times
of India, Euro News, DW English, etc.
• Follow news through RSS and Twitter• Collect tweets pointing to news • No a-priori information on conflicts or
divisions → unsupervised methods
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Carlos Castillo – [email protected]://www.chato.cl/research/
Method
• “Community” of a news source– Users who tweeted at least 3 articles from
that source in the last 3 days
• Collect all articles posted by each– News source– Community of a news source
• Compute distances and project in 2D
Coverage bias
Measure the distribution of the number of words given to each news story.
Compute the 1-divergence between each pair of sources.
Coveragebias
In Twitter, coverage bias (as measured by number of tweets) is evident while selection bias is not.
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Carlos Castillo – [email protected]://www.chato.cl/research/
Future work: find patterns like this?
“perusing TIME’s covers reveals countless examples of the publication tempting the world with critical events, ideas or figures, while dangling before Americans the chance to indulge in trite self-absorption” – David Harris Gershon
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Carlos Castillo – [email protected]://www.chato.cl/research/
Take-home messages
• Encouraging results on fully unsupervised discovery– But results are quite shallow for now
• It is frustratingly difficult to discover bias and framing– We are not happy with only quantifying or
analyzing known conflicts
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Carlos Castillo – [email protected]://www.chato.cl/research/
Journalismneeds
Dataavailability
Computingcapabilities
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Carlos Castillo – [email protected]://www.chato.cl/research/
Journalismneeds
Dataavailability
Computingcapabilities
Overexploited
Finding common ground is not easy.
AI-completeproblems
Poorly planned projects
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Carlos Castillo – [email protected]://www.chato.cl/research/
Data analysis is easy, fun and addictive.
Without good research questions,it is often useless.
Computer science to support a key function of society = Applied computing at its best!
Thank you!Carlos Castillo · [email protected]
http://www.chato.cl/research/
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Carlos Castillo – [email protected]://www.chato.cl/research/
Shouldn't traditional news outlets resent social media?
• We did not take their lunch• I am not pointing fingers but …
• … online classified ads are to “blame”
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Carlos Castillo – [email protected]://www.chato.cl/research/
Data sample from Al Jazeera English
• October 2012≈ 3M visits≈ 606 articles
≈ 200K social media reactions• Open Source Web Analytics beacon
– High-performance process (S4+Cassandra).
Examples (mid-2012)
Decreasing (78%):● Almost all
breaking news
● Sometimes delayed due to timezone differences, e.g. Hurricane Sandy
Steady or Increasing (12%):● Ongoing news:
Obama/Romney, Worker strikes in SA, Syrian unrest
● Articles updated with supporting content
Rebounding (10%):● Articles picked up
by external sources or social media (typically single source of traffic)
● Background articles to new developments
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Carlos Castillo – [email protected]://www.chato.cl/research/
Predicting traffic and shelf-life online has a long history
• Predicting long-term behavior and half-life from short-term observations– Observations = comments, visits, votes, …– Behavior = total comments, total visits, …– 10+ papers specifically on web traffic
• Bit.ly (2011, 2012)– Studies half-life per topic and platform
Results (shelf-life prediction)
Larger improvements for In-Depth articles
Still, this is a 12 hours error in predicting something with an average of 48-72 hours
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Carlos Castillo – [email protected]://www.chato.cl/research/
Social media users engaged with news
• To what extent can they contribute to the journalistic process?
• What kind of roles do they play?
• 47% of journalists from 15 countries (n=478) said Twitter is a source of information for them [source]
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Carlos Castillo – [email protected]://www.chato.cl/research/
Manual annotation
• 200 users in 20 articles• Crowdsourcing workers see:
– Title of news article– Profile and description of user– Sample of 10 tweets of the user
In relation to news providers
Projection in 2D of the second component of a 3-way decomposition with a 3x2x2 core of the tensor of sources x newsmakers x style.
The first component separates football from basketball.
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Carlos Castillo – [email protected]://www.chato.cl/research/
Text pre-processing: steps
• Determine paragraph boundaries– Speech change markers, heuristics based
on text and time
• Apply a part-of-speech tagger– Stanford NLP tagger
• Find named entity mentions• Apply sentiment analysis
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Carlos Castillo – [email protected]://www.chato.cl/research/
News sources
• Non-entity words• Linguistic style
– Prevalence of different part-of-speech classes
• Overall sentiment• Coverage• Timeliness
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Carlos Castillo – [email protected]://www.chato.cl/research/
News matching (model)
• Target: {same story, different story}• Example features:
– Dot product of aboutness scores of resolved entities in the title, body
– Jaccard coefficient of unresolved entities in the title, body
• Logistic regression• 4 models in total, one per genre