If you want to know how people are feeling about the 2012 Olympic Games, just watch that giant Ferris wheel that looms over the River Thames in London. Once a night, the London Eye will light up in a pattern that reflects the prevailing sentiment about the games among Twitter users that day. Positive tweets will turn the thing yellow, negative ones purple.
If it sounds like an epic MIT student prank crossed with a bizarre corporate social media campaign, that’s because that’s pretty much what it is. EDF Energy, a major UK energy company and sponsor of the London Eye, hired a team of MIT engineers to develop an algorithm that scans Olympics-related tweets and assigns them points based on the intensity of positive or negative sentiment expressed therein. If the tweets are, say, 75 percent positive, the London Eye will turn 75 percent yellow.
How does it know what tweets are positive? According to the Telegraph, the algorithm checks the tweets against a library of some 2,750 words and phrases, including emoticons and non-standard English expressions like “omg” and, uh, “totes amazeballs.” Punctuation marks and intensifiers like “very” get factored in as well.
Given all of the snafus that have surfaced in the weeks leading up to the games, you’d think purple might predominate, at least until the actual events begin. But so far yellow has seemed to have the upper hand. (The light shows actually began Thursday night—you can watch them online here or here.)
“I bet the sentiment analysis for the ‘London Eye Twitter lightshow’ is REALLY GOOD at detecting sarcasm,” one wag tweeted.