Social Media News Mining
Carlos Castillo

Gilad Lotan

@ChaToX

@gilgul
Social Media News Mining &
Automatic Content Analysis
of News
Carlos Castillo – Qatar Computing Research Institute

Nov 14...
Outline
• Social media around news
1. Predictive analytics using social media
2. Crowds and curators

• Automatic content ...
Communication scholars
vs. Computer scientists
• Media and communication scholars
– Start from high-level questions

• Com...
Collaborators
•
•
•
•
•
•
•
•
•
•
•

Gianmarco de Francisci Morales – Yahoo!
Mohammed El-Haddad – Al Jazeera
Sandra Gonzál...
Topic 1 of 4

Predictive analytics using
social media
Carlos Castillo, Mohammed El-Haddad, Jürgen Pfeffer and Matt Stempec...
Pirates abduct ship’s crew off Nigerian coast
October 17th, 2012
Usage analysis (in news) online
• Aikat (1998)
– Bursts, short dwell times, weekday != weekend

• Crane and Sornette (2008...
News

In-Depth
News examples
●

●

Dozens killed in India bus-crash
blaze (Oct 30th, 2013)
Kenyan army admits soldiers looted
mall (Oct 3...
News: intense first hour
In-Depth: longer shelf-life
Average visitation/sharing profiles
News

Carlos Castillo – chato@acm.org
http://www.chato.cl/research/

In-Depth

14
Types of news visitation profiles (12 h)
Decreasing (78%)
Steady (9%)
Increasing (3%)
Rebounding (10%)

Carlos Castillo – ...
Prediction of visits
• Short-term traffic is to a large extent
correlated with long-term traffic
• Social media signals ar...
Results (traffic predictions)
Improved
predictions
Using social
media variables
http://fast.qcri.org/
Predictions are updated as new
information arrives. Predictive
models are re-trained every 24
hours. Traffic to many (but ...
Take-home messages
• Decrease, Stay or Increase. Rebound
– Roughly 80:10:10 ratio in first 12 hours

• News vs In-Depth: d...
Topic 2 of 4

News crowds and news
curators in social media
Janette Lehmann, Carlos Castillo, Mounia Lalmas and Ethan Zuck...
Social media
users that are
highly engaged
with news
Transient News Crowds

Carlos Castillo – chato@acm.org
http://www.chato.cl/research/

23
Empirical results
• Experiment with articles in BBC and AJE
• People who tweeted an article within 6 hours of
publication ...
Syria
allows UN
to step
up food
aid
13 Jan 2013

French
troops
launch
ground
combat
in Mali
13 Jan 2013
How do we find the related ones?
• Machine-learning approach
• Important attributes
– Text similarity to original story
– ...
Application to tracking a story

Carlos Castillo – chato@acm.org
http://www.chato.cl/research/

27
Focus on articles → focus on users
Example: which users with a large number of followers tweeted

Syria allows UN to step ...
News curators
• Think Andy Carvin @acarvin, who was a
“distant witness” of the Arab Spring

Carlos Castillo – chato@acm.or...
Do we have curators in Twitter?
Human

Automatic

Topic-unfocused curator
Disseminating news articles
Topic- about diverse...
Which users do we care about?

Human
Topic-focused curator
Collecting interesting information
Topic- with a specific focus...
Manual annotation (200 users)
Focused - Human

Focused - Human

Focused - Auto

Focused - Auto

Unfocused

Unfocused

8%

...
Automatically finding curators
• Simple rules
– UserFracURL >= 85%: automatic
– UserSectionsQ >= 90%: unfocused

• Complex...
Take-home messages
• Twitter users quickly shift topics
– But sometimes return to a topic

• There are excellent news cura...
Topic 3 of 4

Analysis of TV news via
closed captions
Carlos Castillo, Gianmarco De Francisci Morales, Marcelo Mendoza, Na...
Acquiring closed captions
• We used data from
Yahoo's IntoNow
– 140 TV channels
– 2MB/channel/day
– Jan-Jun 2012

• Intern...
Text pre-processing: input
[1339302660] WHAT MORE CAN YOU ASK FOR?
[1339302662] >> THIS IS WHAT NBA
[1339302663] BASKETBAL...
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: Nat...
Clusters by non-entity words
General news
Sport news
General + entertainment
Sports
Sports
General news
Sports
General + s...
Clusters by linguistic style
General + business

General + entertainment

Sports
Sorting by average sentiment
Sentiment scores
on TV captions go
from neutral to
positive.

Strong positive
words are used
...
Automatic TV ↔ online news matching
• Same pre-processing is done over
articles on the Yahoo! News website
• Genre classif...
Coverage by prominence
TV networks
with more
resources can
cover more
stories.
Some prefer
to cover only
prominent
ones, o...
US military to probe “marine abuse video”
January 12th, 2012
Breaking stories vs news matching
Average story duration

Sports stories tend to have a longer life
Newsmakers
• By professional
activity
– Sentiments
– Distributions

• In relationship to news
providers
• Everybody is a
(...
By professional activity
Athletes or entertainers?
Politicians or entertainers?
Take-home messages
• Closed captions are a goldmine of
data for content analysis
• Automatic content analysis is
feasible ...
Topic 4 of 4

Biases in online news in
international news media
Diego Sáez-Trumper, Carlos Castillo and Mounia Lalmas:
Soc...
Jonathan Stray
The Atlantic, Feb 2013

Wei Hao-Lin
PhD Thesis, CMU 2008
Selection bias

Coverage bias

Statement bias

Carlos Castillo – chato@acm.org
http://www.chato.cl/research/

55
Goal: discover bias in news media
• 60+ news sources in English
– BBC, CNN, Fox, Time, UPI, Herald Sun, Times
of India, Eu...
Method
• “Community” of a news source
– Users who tweeted at least 3 articles from
that source in the last 3 days

• Colle...
Community
overlaps
(J>0.03)
Selection bias
Coverage bias
Measure the distribution of
the number of words given
to each news story.
Compute the 1-divergence
between e...
Coverage
bias
In Twitter,
coverage bias (as
measured by
number of tweets)
is evident while
selection bias is
not.
Coverage bias and partisan politics
Sentiment analysis
Future work: find patterns like this?
“perusing TIME’s covers reveals countless
examples of the publication tempting the w...
Take-home messages
• Encouraging results on fully
unsupervised discovery
– But results are quite shallow for now

• It is ...
Closing remarks
Journalism
needs
Data
availability

Carlos Castillo – chato@acm.org
http://www.chato.cl/research/

Computing
capabilities
...
Finding common
ground is not easy.

AI-complete
problems

Journalism
needs

Data
availability

Poorly planned
projects

Co...
Data analysis is easy, fun and addictive.
Without good research questions,
it is often useless.
Computer science to suppor...
Thank you!
Carlos Castillo · chato@acm.org
http://www.chato.cl/research/
Shouldn't traditional news outlets
resent social media?
• We did not take their lunch
• I am not pointing fingers but …

•...
Data sample from Al Jazeera English
• October 2012
≈ 3M visits
≈ 606 articles
≈ 200K social media reactions
• Open Source ...
News: less shared on Facebook
In-Depth: more shared on Facebook
Examples (mid-2012)
Decreasing
(78%):
●

●

Almost all
breaking news
Sometimes
delayed due to
timezone
differences, e.g.
H...
Predicting traffic and shelf-life online
has a long history
• Predicting long-term behavior and
half-life from short-term ...
Results (shelf-life prediction)

Larger
improvements
for In-Depth
articles
Still, this is a 12 hours
error in predicting
s...
Social media users engaged with news
• To what extent can they contribute to
the journalistic process?
• What kind of role...
Manual annotation
• 200 users in 20 articles
• Crowdsourcing workers see:
– Title of news article
– Profile and descriptio...
In relation to news providers

Projection in 2D of the second component of a 3-way decomposition
with a 3x2x2 core of the ...
Text pre-processing: steps
• Determine paragraph boundaries
– Speech change markers, heuristics based
on text and time

• ...
News sources
• Non-entity words
• Linguistic style
– Prevalence of different part-of-speech
classes

• Overall sentiment
•...
News matching (model)
• Target: {same story, different story}
• Example features:
– Dot product of aboutness scores of res...
Social Media News Mining and Automatic Content Analysis of News
Social Media News Mining and Automatic Content Analysis of News
Social Media News Mining and Automatic Content Analysis of News
Social Media News Mining and Automatic Content Analysis of News
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Social Media News Mining and Automatic Content Analysis of News

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Presentation at the Tow Center for Digital Journalism, Columbia University. November 14th, 2013.

VIDEO: http://new.livestream.com/accounts/1079539/events/2542929

http://towcenter.org/events/conversation-with-carlos-castillo/

Social Media News Mining and Automatic Content Analysis of News

  1. 1. Social Media News Mining Carlos Castillo Gilad Lotan @ChaToX @gilgul
  2. 2. Social Media News Mining & Automatic Content Analysis of News Carlos Castillo – Qatar Computing Research Institute Nov 14th, 2013
  3. 3. Outline • Social media around news 1. Predictive analytics using social media 2. Crowds and curators • Automatic content analysis of news 3. TV news via closed captions 4. Online news in international media Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 5
  4. 4. Communication scholars vs. 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 Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 6
  5. 5. 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 Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 7
  6. 6. Topic 1 of 4 Predictive analytics using social media Carlos Castillo, Mohammed El-Haddad, Jürgen Pfeffer and Matt Stempeck Characterizing the Life Cycle of Online News Stories Using Social Media Reactions To appear in Proc. of Computer Supported Collaborative Work and Social Media. Baltimore, MD, USA. February 2014. See also: demo at http://fast.qcri.org/
  7. 7. Pirates abduct ship’s crew off Nigerian coast October 17th, 2012
  8. 8. 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! Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 10
  9. 9. News In-Depth
  10. 10. News examples ● ● Dozens killed in India bus-crash blaze (Oct 30th, 2013) Kenyan army admits soldiers looted mall (Oct 30th, 2013) In-Depth examples ● ● 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)
  11. 11. News: intense first hour In-Depth: longer shelf-life
  12. 12. Average visitation/sharing profiles News Carlos Castillo – chato@acm.org http://www.chato.cl/research/ In-Depth 14
  13. 13. Types of news visitation profiles (12 h) Decreasing (78%) Steady (9%) Increasing (3%) Rebounding (10%) Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 15
  14. 14. 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 traffic More discussion → longer shelf-life • Can we predict 7 days after 30 minutes? Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 16
  15. 15. Results (traffic predictions) Improved predictions Using social media variables
  16. 16. http://fast.qcri.org/
  17. 17. 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. http://fast.qcri.org/
  18. 18. 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 Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 20
  19. 19. Topic 2 of 4 News crowds and news curators in social media Janette Lehmann, Carlos Castillo, Mounia Lalmas and Ethan Zuckerman: Transient News Crowds in Social Media In 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 Twitter Social News on the Web (SNOW) workshop. Rio de Janeiro, Brazil, May 2013. See also: blog post.
  20. 20. Social media users that are highly engaged with news
  21. 21. Transient News Crowds Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 23
  22. 22. 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 Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 24
  23. 23. Syria allows UN to step up food aid 13 Jan 2013 French troops launch ground combat in Mali 13 Jan 2013
  24. 24. 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) Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 26
  25. 25. Application to tracking a story Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 27
  26. 26. Focus on articles → focus on users Example: which users with a large number of followers tweeted Syria allows UN to step up food aid (16 Jan 2013) Twitter user Followers Tweets about ... @RevolutionSyria 88,122 Syria @KenanFreeSyria 13,388 Syria 703 Food @UP_food @KeriJSmith @BreakingNews 8,838 Breaking news/top stories 5,662,866 Breaking news/top stories Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 28
  27. 27. News curators • Think Andy Carvin @acarvin, who was a “distant witness” of the Arab Spring Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 29
  28. 28. Do we have curators in Twitter? Human Automatic Topic-unfocused curator Disseminating news articles Topic- about diverse topics, usually unfocus breaking news/top stories ed @KeriJSmith News aggregators Collecting news articles (e.g. from RSS feeds) and automatically post their corresponding headlines and URLs @BreakingNews Topic-focused curator Collecting interesting information Topic- with a specific focus, usually a focused geographic region or a topic @KenanFreeSyria Topic-focused aggregators Disseminating automatically news with topical focus Carlos Castillo – chato@acm.org http://www.chato.cl/research/ @UP_food, @RevolutionSyria 30
  29. 29. Which users do we care about? Human Topic-focused curator Collecting interesting information Topic- with a specific focus, usually a focused geographic region or a topic @KenanFreeSyria Carlos Castillo – chato@acm.org http://www.chato.cl/research/ Automatic Topic-focused aggregators Disseminating automatically news with topical focus @UP_food, @RevolutionSyria 31
  30. 30. Manual annotation (200 users) Focused - Human Focused - Human Focused - Auto Focused - Auto Unfocused Unfocused 8% 13% 3% 2% 95% 79% Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 32
  31. 31. Automatically finding curators • Simple rules – UserFracURL >= 85%: automatic – UserSectionsQ >= 90%: unfocused • Complex model (AUC > 0.90) – Random forest Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 33
  32. 32. 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 Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 34
  33. 33. Topic 3 of 4 Analysis of TV news via closed captions Carlos Castillo, Gianmarco De Francisci Morales, Marcelo Mendoza, Nasir Khan: Says Who? Automatic Text-based Content Analysis of Television News Workshop on Mining Unstructured Data Using NLP (UnstructureNLP). Burlington, CA, USA. October 2013.
  34. 34. 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 Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 36
  35. 35. Text pre-processing: input [1339302660] WHAT MORE CAN YOU ASK FOR? [1339302662] >> THIS IS WHAT NBA [1339302663] BASKETBALL IS ABOUT Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 37
  36. 36. 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] Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 38
  37. 37. Clusters by non-entity words General news Sport news General + entertainment Sports Sports General news Sports General + sports Business + sports Business + sports
  38. 38. Clusters by linguistic style General + business General + entertainment Sports
  39. 39. Sorting by average sentiment Sentiment scores on TV captions go from neutral to positive. Strong positive words are used more than strong negative words? Mixed Sports
  40. 40. 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 Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 42
  41. 41. Coverage by prominence TV networks with more resources can cover more stories. Some prefer to cover only prominent ones, others want some niche content.
  42. 42. US military to probe “marine abuse video” January 12th, 2012
  43. 43. Breaking stories vs news matching
  44. 44. Average story duration Sports stories tend to have a longer life
  45. 45. Newsmakers • By professional activity – Sentiments – Distributions • In relationship to news providers • Everybody is a (potential) entertainer Carlos Castillo – chato@acm.org http://www.chato.cl/research/ Distributions of mentions per person 47
  46. 46. By professional activity
  47. 47. Athletes or entertainers?
  48. 48. Politicians or entertainers?
  49. 49. 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 Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 51
  50. 50. Topic 4 of 4 Biases in online news in international news media Diego Sáez-Trumper, Carlos Castillo and Mounia Lalmas: Social Media News Communities: Gatekeeping, Coverage, and Statement Bias In Proc. of Conference on Information and Knowledge Management (short paper). Burlingame, CA, USA, October 2013.
  51. 51. Jonathan Stray The Atlantic, Feb 2013 Wei Hao-Lin PhD Thesis, CMU 2008
  52. 52. Selection bias Coverage bias Statement bias Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 55
  53. 53. 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 Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 56
  54. 54. 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 Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 57
  55. 55. Community overlaps (J>0.03)
  56. 56. Selection bias
  57. 57. Coverage bias Measure the distribution of the number of words given to each news story. Compute the 1-divergence between each pair of sources.
  58. 58. Coverage bias In Twitter, coverage bias (as measured by number of tweets) is evident while selection bias is not.
  59. 59. Coverage bias and partisan politics
  60. 60. Sentiment analysis
  61. 61. 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 Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 64
  62. 62. 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 Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 65
  63. 63. Closing remarks
  64. 64. Journalism needs Data availability Carlos Castillo – chato@acm.org http://www.chato.cl/research/ Computing capabilities 67
  65. 65. Finding common ground is not easy. AI-complete problems Journalism needs Data availability Poorly planned projects Computing capabilities Overexploited Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 68
  66. 66. 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! Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 69
  67. 67. Thank you! Carlos Castillo · chato@acm.org http://www.chato.cl/research/
  68. 68. 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” Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 72
  69. 69. 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). Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 73
  70. 70. News: less shared on Facebook In-Depth: more shared on Facebook
  71. 71. Examples (mid-2012) Decreasing (78%): ● ● Almost all breaking news Sometimes delayed due to timezone differences, e.g. Hurricane Sandy Steady or Rebounding Increasing (12%): (10%): ● ● Ongoing news: Obama/Romney, Worker strikes in SA, Syrian unrest Articles updated with supporting content ● ● Articles picked up by external sources or social media (typically single source of traffic) Background articles to new developments
  72. 72. 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 Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 76
  73. 73. 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
  74. 74. 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] Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 78
  75. 75. 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 Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 79
  76. 76. 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.
  77. 77. 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 Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 81
  78. 78. News sources • Non-entity words • Linguistic style – Prevalence of different part-of-speech classes • Overall sentiment • Coverage • Timeliness Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 82
  79. 79. 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 Carlos Castillo – chato@acm.org http://www.chato.cl/research/ 83

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