1. 1 From Sentiment to Emotion Analysis in Social Networks Jie Tang Department of Computer Science and Technology Tsinghua University, China

2. 2 Social Networks >1000 million users The 3 rd largest “Country” in the world More visitors than Google More than 6 billion images 2009, 2 billion tweets per quarter 2010, 4 billion tweets per quarter 2011, tweets per quarter >800 million users Pinterest, with a traffic higher than Twitter and Google 25 billion 2013, users, 40 % yearly increase 560 million

3. 3 A Trillion Dollar Opportunity Social networks already become a bridge to connect our daily physical life and the virtual web space On2Off [1] [1] Online to Offline is trillion dollar business http://techcrunch.com/2010/08/07/why-online2offline-commerce-is-a-trillion-dollar-opportunity/

4. 4 Core Research in Social Network BIG Social Data Social Theories Algorithmic Foundations BA model Social influence Action Social Network Analysis Theory PredictionSearch Information Diffusion Advertise Application MacroMesoMicro ER modelCommunity Group behavior DunbarSocial tie

5. 5 Today, let us start with sentiment analysis…

6. 6 “Love Obama” I love Obama Obama is great! Obama is fantastic I hate Obama, the worst president ever He cannot be the next president! No Obama in 2012! Positive Negative

7. 7 Homophily and Influence Homophily —“birds of a feather flock together” –A user in the social network tends to be similar to their connected neighbors. Originated from different mechanisms –Influence Indicates people tend to follow the behaviors of their friends –Selection Indicates people tend to create relationships with other people who are already similar to them –Confounding variables Other unknown variables exist, which may cause friends to behave similarly with one another.

8. 8 Twitter Data Twitter –1,414,340 users and 480,435,500 tweets –274,644,047 t-follow edges and 58,387,964 @ edges –Manually labeled thousands of users [1] Chenhao Tan, Lillian Lee, Jie Tang, Long Jiang, Ming Zhou, and Ping Li. User-level sentiment analysis incorporating social networks. In KDD’11, pages 1397–1405, 2011. An example: “#lakers b**tch!” =? √ X

9. 9 Influence Shared sentiment conditioned on type of connection.

10. 10 Selection Connectedness conditioned on labels

11. 11 Question: what drives users’ sentiments?

12. 12 Sentiment vs. Emotion Charles Darwin: –Emotion serves as a purpose for humans in aiding their survival during the evolution. [1] Emotion is the driving force of user’s sentiments… Emotion stimulates the mind 3000 times quicker than rational thought! [1] Charles Darwin. The Expression of Emotions in Man and Animals. John Murray, 1872.

13. 13 “Happy” System Can we predict users’ emotion?

14. 14 Observations (cont.) Location correlation (Red-happy) Activity correlation Karaoke ? ? ? ? ? GYM Dorm The Old Summer Palace Classroom

15. 15 Observations (a) Social correlation (a) Implicit groups by emotions (c) Calling (SMS) correlation

16. 16 Observations (cont.) Temporal correlation

17. 17 Methodologies

18. 18 MoodCast: Dynamic Continuous Factor Graph Model Our solution 1. We directly define continuous feature function; 2. Use Metropolis-Hasting algorithm to learn the factor graph model. [1] Jie Tang, Yuan Zhang, Jimeng Sun, Jinghai Rao, Wenjing Yu, Yiran Chen, and ACM Fong. Quantitative Study of Individual Emotional States in Social Networks. IEEE TAC, 2012, Volume 3, Issue 2, Pages 132-144.

19. 19 Problem Formulation G t =(V, E t, X t, Y t ) Attributes: - Location: Lab - Activity: Working Emotion: Sad Learning Task: Time t Time t-1, t-2…

20. 20 Dynamic Continuous Factor Graph Model Time t’ Time t : Binary function

21. 21 Learning with Factor Graphs Temporal Social Attribute y3y3 y4y4 y5y5 y2y2 y1y1 y'3y'3

22. 22 MH-based Learning algorithm [1] Yuan Zhang, Jie Tang, Jimeng Sun, Yiran Chen, and Jinghai Rao. MoodCast: Emotion Prediction via Dynamic Continuous Factor Graph Model. In ICDM’10. pp. 1193-1198.

23. 23 Still Challenges Q1: Are there any other social factor that may affect the prediction results? Q2: How to scale up the model to large networks?

24. 24 Q1: Conformity Influence I love Obama Obama is great! Obama is fantastic Positive Negative 2. Individual 3. Group conformity 1. Peer influence [1] Jie Tang, Sen Wu, and Jimeng Sun. Confluence: Conformity Influence in Large Social Networks. In KDD’13, 2013.

25. 25 Conformity Factors Individual conformity Peer conformity Group conformity All actions by user v A specific action performed by user v at time t

26. 26 Q2: Distributed Learning Slave Compute local gradient via random sampling Slave Compute local gradient via random sampling Master Global update Master Global update Graph Partition by Metis Master-Slave Computing Inevitable loss of correlation factors!

27. 27 Random Factor Graphs Master: Optimize with Gradient Descent Slave: Distributedly compute Gradient via LBP Master-Slave Computing Gradients Parameters K=1 K=2 Continue to increase K

28. 28 Model Inference Calculate marginal probability in each subgraph Aggregate the marginal probability and normalize

29. 29 Theoretical Analysis Θ * : Optional parameter of the complete graph Θ: Optional parameter of the subgraphs P s,j : True marginal distributions on the complete graph G * s,j : True marginal distributions on subgraphs Let E s,j = log G * s,j – log P s,j ， we have:

30. 30 Experiments

31. 31 Results for Sentiment Analysis Twitter –1,414,340 users and 480,435,500 tweets –274,644,047 t-follow edges and 58,387,964 @ edges Baseline –SVM Vote Measures –Accuracy and Macro F1

32. 32 Performance

33. 33 Results of Different Learning Algorithms

34. 34

35. 35 Data Set Baseline –SVM –SVM with network features –Naïve Bayes –Naïve Bayes with network features Evaluation Measure: Precision, Recall, F1-Measure #UsersAvg. Links#LabelsOther MSN303.29,869>36,000hr LiveJournal469,70749.62,665,166 Results for Emotion Analysis

36. 36 Performance Result

37. 37 Factor Contributions All factors are important for predicting user emotions Mobile

38. 38 Online Applications: Emotion Analysis on Flickr

39. 39

40. 40  Framework: Images -Aesthetic Effects -Emotions  Model: Factor Graphs for images in Social Networks [1] Jia Jia, Sen Wu, Xiaohui Wang, Peiyun Hu, Lianhong Cai, and Jie Tang. Can We Understand van Gogh’s Mood? Learning to Infer Affects from Images in Social Networks. In ACM Multimedia. pp. 857-860. [2 ] Grand Challenge 2nd Prize Award

41. 41 App1: Emotion Distribution on Flickr Before Thanksgiving 2011 VS During Thanksgiving holiday Happy, Cheerful, and Peaceful 100,000 Images from Flickr

42. 42 App2: Modify Images with Emotional Words Happy Natural Clear Original Image Summer? Autumn? Winter? More than 180 different effects

43. 43 Summary

44. 44 Summary Social networks bring revolutionary changes to the Web and unprecedented opportunities for us Emotion stimulates minds 3000 times faster than rational thoughts! Embedding social theories into sentiment/emotion analysis can benefit many applications

45. 45 Related Publications Jie Tang, Jimeng Sun, Chi Wang, and Zi Yang. Social Influence Analysis in Large-scale Networks. In KDD'09, pages 807-816, 2009. Chenhao Tan, Lillian Lee, Jie Tang, Long Jiang, Ming Zhou, and Ping Li. User-level sentiment analysis incorporating social networks. In KDD’11, pages 1397–1405, 2011. Jie Tang, Sen Wu, and Jimeng Sun. Confluence: Conformity Influence in Large Social Networks. In KDD’13. Jie Tang, Yuan Zhang, Jimeng Sun, Jinghai Rao, Wenjing Yu, Yiran Chen, and ACM Fong. Quantitative Study of Individual Emotional States in Social Networks. IEEE Transactions on Affective Computing (TAC), 2012, Volume 3, Issue 2, Pages 132-144. (Selected as the Spotlight Paper) Yuan Zhang, Jie Tang, Jimeng Sun, Yiran Chen, and Jinghai Rao. MoodCast: Emotion Prediction via Dynamic Continuous Factor Graph Model. In ICDM’10. pp. 1193-1198. Jia Jia, Sen Wu, Xiaohui Wang, Peiyun Hu, Lianhong Cai, and Jie Tang. Can We Understand van Gogh’s Mood? Learning to Infer Affects from Images in Social Networks. In ACM MM, pages 857-860, 2012. Xiaohui Wang, Jia Jia, Peiyun Hu, Sen Wu, Lianhong Cai, and Jie Tang. Understanding the Emotional Impact of Images. (Grand Challenge) In ACM MM. pp. 1369-1370. (Grand Challenge 2nd Prize Award)

46. 46 Thanks you ！ Collaborators: Lillian Lee, Chenhao Tan (Cornell) Ming Zhou, Long Jiang (Microsoft), Yuan Zhang (MIT) Jimeng Sun (IBM), Jinghai Rao (Nokia) Sen Wu, Jia Jia, Xiaohui Wang, Yiran Chen, Wenjing Yu (THU) Jie Tang, KEG, Tsinghua U, http://keg.cs.tsinghua.edu.cn/jietanghttp://keg.cs.tsinghua.edu.cn/jietang Download data & Codes, http://arnetminer.org/downloadhttp://arnetminer.org/download