1. Panagiotis T. Metaxas CS, Wellesley College & CRCS, Harvard University Joint work with Eni Mustafaraj and Dani Gayo-Avello

2. Overview Social Media can “predict the present/future” Success stories Electoral Predictions with Social Media Successful Predictions Can Twitter predict US Elections? Elsewhere: Can Google Trends predict US Elections? How To Predict Elections using Social Media

3. Social Media can “predict the future” (?!)

4. To Predict (according to Merriam-Webster)

5. Successful Electoral Predictions This slide was intentionally left blank

6. Successful Would-be Predictions Methods Used: Raw volume of Tweets Sentiment Analysis of Tweets Data Used: 2009 German Elections Tweets 2008 US Presidential Elections Tweets Our Data: 2010 Special Senatorial Elections (MA) Tweets 2010 Senatorial Elections (CO, NV, CA, KY, DE) Tweets

7. Can Twitter Volume Predict? Twitter volume (would have) predicted correctly 50% of the high-visibility US Congressional races

8. Can Tweet Sentiment Predict? Sentiment analysis (would have) predicted correctly 50% of the high-visibility US Congressional races But was it sensing the sentiment correctly?

9. “What if you had used some other methods?” We did not invent the methods we used, we just evaluated them on data other than those they were designed for We started off expecting to predict successfully (In fact, we were “predicting” at times ;-) But we learned a lot from these experiments: How to Predict Using Social Media

10. How To Predict A method of prediction should be an algorithm finalized before the elections: (input) how Social Media data are to be collected, including the dates of data collection, (filter) the way in which the cleanup of the data is to be performed (e.g., the selection of keywords relevant to the election), (method) the algorithms to be applied on the data along with their input parameters, and (output) the semantics under which the results are to be interpreted.

11. How To Predict A method of prediction should be an algorithm. Data from Social Media are fundamentally different than Data from Natural Phenomena. People will change their behavior the next time around Spammers & Activists will try to take advantage e.g. “Twitter Bomb” and “Prefab Tweeter Factory”

12. How To Predict A method of prediction should be an algorithm. Data from Social Media are fundamentally different than Data from Natural Phenomena. Form a testable theory on why and when it predicts. Go past the OMG! Factor Avoid the self-deception syndrome

13. How To Predict A method of prediction should be an algorithm. Data from Social Media are fundamentally different than Data from Natural Phenomena. Form a testable theory on why and when it predicts. (maybe) Learn from the professional pollsters. Tweet ≠ User User ≠ Eligible Voter Eligible Voter ≠ Voter

15. Thank you!