By Evan Nesterak, Behavioral Scientist
My girlfriend, Klára, considers herself something of a movie buff. For the most part this is a good thing. I have a trusted and reliable source for what to watch when it’s time to kick back.
But there is a downside.
Whenever I suggest something to watch, she’s pretty skeptical. Her first reaction is to check the ratings online and report back that, just as she suspected, the movie can’t be any good because it’s only been rated seven-and-a-half stars. She’ll trust me with big financial decisions, for instance, but a 90-minute movie seems a step too far. For that, she’d rather believe a group of strangers on the internet.
But how reliable are those movie ratings? A series of studies (open-access), recently published in Nature Human Behaviour, suggests those ratings might not be the best way to pick your next movie. A research team, led by Matthew Rocklage, assistant professor of marketing at the University of Massachusetts–Boston, explored how online ratings (e.g., four out of five stars) of movies, restaurants, books, and commercials related to that thing’s success. The team also explored how the language people use in reviews, particularly the level of emotion, related to success. What the researchers found was that emotionality of reviews did a better job than star rankings at predicting which reviewee performed better—more box office sales for movies, more reservations for restaurants.
This is in part because ratings tend to skew heavily positive, so much so that the ratings cease to be useful in differentiating between one movie or another, something Rocklage and his collaborators have dubbed the positivity problem. (It’s curious to think that positivity could be a problem online, when we so often focus on the issues caused by negativity in the digital sphere.)