Guest Post: Who won the debate? Ask Twitter

Image by Donkey Hotey via Flickr

Image by Donkey Hotey via Flickr

As expected, last night’s VP debate was engaging, to say the least. David Lazer‘s lab was at it again, analyzing real-time Twitter data to gauge the public’s response to the event. Below, Lazer explains their Twitter “winning index,” which fluctuated across the two candidates’ performances.


Twitter allows real-time calculation of audience responses to the debate.  The “Winning Index” produced by our lab shows how different groups evaluated the candidates’ performances during the debate.  The index tracks the extent to which tweets from a group of users mention a candidate with ‘winning words” like “won” or “victory.”  The index shows clear partisan disagreement when the debate ended at 10:30 (22:30).  The blue line — comprised of Democratic leaning tweeters — declares victory for Biden.  The red line — comprised of Republican leaning tweeters — declares victory for Ryan.  Interestingly, the bi-partisan tweeters — many of whom are media professionals — appear to side with the Democrats on this one.

Inspection of the index and another tool, tells the story of how the debate was “won” (in the minds of these different groups).  The Democratic tweeters began in the doldrums, tracking closely to the Republican line, suggesting they think that Ryan is winning.  At around 9:30, however, there is a dramatic change.  The blue line soars and remains high for the rest of the debate.  This appears to be when Biden restored the confidence of anxious Democrats.  Republicans soon follow suit about 10 minutes later declaring Ryan is winning.  The green group is less extreme in its reaction until the end of the debate.

There are early signs, however, that the green group was favoring Biden.  The sentiment index tracks the affect of words used in tweets about the candidates.  Greens and showed pro-Obama/Biden sentiment consistently through most of the debate.