Jul 2, 2014

Marti Hearst on Text Analytics and Facebook's Experimentation with Users' Emotions

From Wired

Don’t Worry, Facebook Still Has No Clue How You Feel

By Marcus Wohlsen

The claim is as bold as it is creepy: “Emotional states can be transferred to others via emotional contagion, leading people to experience the same emotions without their awareness.”

The data backing this claim—as you’ve likely heard by now—comes from an experiment conducted by Facebook on nearly 700,000 of its users without their knowledge....

Even in the most stripped-down scenario however—where you assume everyone is being honest and unironic—sentiment analysis still has a long way to go. For basic binary choices, the most advanced sentiment analysis techniques have been shown to be between 70 and 80 percent accurate, says Marti Hearst, a professor at the University of California, Berkeley’s School of Information and one of the early pioneers of text analytics in the late 1990s. That rate sounds pretty good, but consider that 50 percent accuracy is the equivalent of flipping a coin. “That’s a really simple algorithm, and that’s going to have a lot of error,” Hearst says of binary sentiment analyses like the kind used in the Facebook study. “But when you do a study like this with hundreds of thousands of data points, you typically say: ‘The error is going to come out in the wash.’”

Read more...

Last updated:

October 4, 2016