Social Media News Communities: Gatekeeping, Coverage, and Statement Bias
-
Upload
mounia-lalmas -
Category
Social Media
-
view
1.380 -
download
7
description
Transcript of Social Media News Communities: Gatekeeping, Coverage, and Statement Bias
![Page 1: Social Media News Communities: Gatekeeping, Coverage, and Statement Bias](https://reader034.fdocuments.us/reader034/viewer/2022051322/53fd3b998d7f72e61c8b4700/html5/thumbnails/1.jpg)
Social Media News Communities:Gatekeeping, Coverage, and Statement
Bias
Diego Saez-Trumper∗1 Carlos Castillo† Mounia Lalmas‡
∗Universitat Pompeu Fabra, Barcelona†Qatar Computing Research Institute, Doha
‡Yahoo Labs London
San Francisco, October, 2013
1This work was done while visiting the Qatar Computing Research Institute
![Page 2: Social Media News Communities: Gatekeeping, Coverage, and Statement Bias](https://reader034.fdocuments.us/reader034/viewer/2022051322/53fd3b998d7f72e61c8b4700/html5/thumbnails/2.jpg)
”Media bias refers to (...) the selection of which stories arereported and how they are reported”. S. Rivolta
![Page 3: Social Media News Communities: Gatekeeping, Coverage, and Statement Bias](https://reader034.fdocuments.us/reader034/viewer/2022051322/53fd3b998d7f72e61c8b4700/html5/thumbnails/3.jpg)
Selection
Coverage
Statement
![Page 4: Social Media News Communities: Gatekeeping, Coverage, and Statement Bias](https://reader034.fdocuments.us/reader034/viewer/2022051322/53fd3b998d7f72e61c8b4700/html5/thumbnails/4.jpg)
Selection
Coverage
Statement
![Page 5: Social Media News Communities: Gatekeeping, Coverage, and Statement Bias](https://reader034.fdocuments.us/reader034/viewer/2022051322/53fd3b998d7f72e61c8b4700/html5/thumbnails/5.jpg)
Selection
Coverage
Statement
![Page 6: Social Media News Communities: Gatekeeping, Coverage, and Statement Bias](https://reader034.fdocuments.us/reader034/viewer/2022051322/53fd3b998d7f72e61c8b4700/html5/thumbnails/6.jpg)
Selection
Coverage
Statement
![Page 7: Social Media News Communities: Gatekeeping, Coverage, and Statement Bias](https://reader034.fdocuments.us/reader034/viewer/2022051322/53fd3b998d7f72e61c8b4700/html5/thumbnails/7.jpg)
Goal: quantify biases present in onlinenews
![Page 8: Social Media News Communities: Gatekeeping, Coverage, and Statement Bias](https://reader034.fdocuments.us/reader034/viewer/2022051322/53fd3b998d7f72e61c8b4700/html5/thumbnails/8.jpg)
Challenges
I Consider a large set of news sources.I Compare news sources with social media (Twitter).I Use unsupervised methods.
![Page 9: Social Media News Communities: Gatekeeping, Coverage, and Statement Bias](https://reader034.fdocuments.us/reader034/viewer/2022051322/53fd3b998d7f72e61c8b4700/html5/thumbnails/9.jpg)
Data set - News Sources
I Use the top-100 news websites from Alexa.com.I Download all the news they publish trough RSS and
Twitter.
![Page 10: Social Media News Communities: Gatekeeping, Coverage, and Statement Bias](https://reader034.fdocuments.us/reader034/viewer/2022051322/53fd3b998d7f72e61c8b4700/html5/thumbnails/10.jpg)
Data set - Twitter
Download all tweets containing a URL pointing to a newssource.
Community 6= Followers
People who have tweeted at least K1 articles from a given newssource within K2 days.
![Page 11: Social Media News Communities: Gatekeeping, Coverage, and Statement Bias](https://reader034.fdocuments.us/reader034/viewer/2022051322/53fd3b998d7f72e61c8b4700/html5/thumbnails/11.jpg)
Selection Bias (Gatekeeping)
I Compute similarity among news sources using the Jaccardcoefficient.
I Project it in two dimensions using PCA.
![Page 12: Social Media News Communities: Gatekeeping, Coverage, and Statement Bias](https://reader034.fdocuments.us/reader034/viewer/2022051322/53fd3b998d7f72e61c8b4700/html5/thumbnails/12.jpg)
Selection Bias (Gatekeeping)
News Sources
Geographical pattern
No clear pattern.
![Page 13: Social Media News Communities: Gatekeeping, Coverage, and Statement Bias](https://reader034.fdocuments.us/reader034/viewer/2022051322/53fd3b998d7f72e61c8b4700/html5/thumbnails/13.jpg)
Coverage
I Compute similarity among news sources using theJensen-Shannon divergence (JS) .
Coverage Bias(s1, s2) = 1− JS(s1, s2)
![Page 14: Social Media News Communities: Gatekeeping, Coverage, and Statement Bias](https://reader034.fdocuments.us/reader034/viewer/2022051322/53fd3b998d7f72e61c8b4700/html5/thumbnails/14.jpg)
Coverage Bias
News Sources
Stronger geographical pattern.
![Page 15: Social Media News Communities: Gatekeeping, Coverage, and Statement Bias](https://reader034.fdocuments.us/reader034/viewer/2022051322/53fd3b998d7f72e61c8b4700/html5/thumbnails/15.jpg)
Coverage Bias
Geographical pattern.
![Page 16: Social Media News Communities: Gatekeeping, Coverage, and Statement Bias](https://reader034.fdocuments.us/reader034/viewer/2022051322/53fd3b998d7f72e61c8b4700/html5/thumbnails/16.jpg)
Political leaning
News Sources Twitter
Stronger political leaning signal in Twitter.
![Page 17: Social Media News Communities: Gatekeeping, Coverage, and Statement Bias](https://reader034.fdocuments.us/reader034/viewer/2022051322/53fd3b998d7f72e61c8b4700/html5/thumbnails/17.jpg)
Statement
I Use sentiment analyses to find positive/negativesentiments associated to a person.
![Page 18: Social Media News Communities: Gatekeeping, Coverage, and Statement Bias](https://reader034.fdocuments.us/reader034/viewer/2022051322/53fd3b998d7f72e61c8b4700/html5/thumbnails/18.jpg)
Statement
Obama Thatcher
Sentiments are more extreme in Twitter.
![Page 19: Social Media News Communities: Gatekeeping, Coverage, and Statement Bias](https://reader034.fdocuments.us/reader034/viewer/2022051322/53fd3b998d7f72e61c8b4700/html5/thumbnails/19.jpg)
Conclusions
I Strong geographical patterns.I Political leaning signal is stronger in Social Media.I Feelings are more extreme in Social Media.