The Dot Matrix
Some maps show us where to go. But the ones created at Columbia's Spatial Information Design Lab may show us where we're headed.by David J. Craig Published Summer 2012
For one week in July 2011, a computer in SIDL’s office at the architecture school downloaded the content of every Foursquare update from New York City, Moscow, Beijing, Tokyo, Rio de Janeiro, Mexico City, and Mumbai. By the week’s end, people in these cities had posted more than two million updates. Williams, using another computer program she created for the task, then translated the information into dots whose colors represent the type of activity popular at a location — green for outdoor activities, mauve for arts events, yellow for dining, hot pink for nightlife, and so forth — and whose sizes represent the number of Foursquare users engaged in the activity.
The brilliantly colored maps do hint at patterns: in Tokyo, young people in search of nightlife cluster around subway stops; in Rio, they rarely venture from Ipanema beach; and in Moscow, shoppers populate the city’s outer rings, where several Western-style megamalls have been built in recent years.
Heading into the project, Williams had expected to find Foursquare activity in New York City concentrated in wealthy and white neighborhoods. If this were true, she thought, it would suggest a digital divide in social-media use with implications for, among other things, how city agencies and nonprofits communicate with those who need their services. “Imagine you’re a health-care organizer trying to educate people about air-quality problems,” she says. “Should you use social media? That’s a popular strategy right now. But are people in poor neighborhoods really using these sites? That’s difficult to know.”
In fact, her map shows that New Yorkers across the entire city, from Chelsea to Harlem and Brownsville to the South Bronx, are using Foursquare regularly. (While most activity occurs in Midtown and Lower Manhattan, the number of updates in those areas is proportional to their density.)
“New York is a social-media city, top to bottom,” says Williams, who was recently invited by Mayor Michael Bloomberg’s office to show city officials how they might use her methods to learn which public squares and parks are busiest. “We found patterns in the data that you couldn’t see before — stories that didn’t exist. The maps really make them pop.”
Douglas Quenqua contributed reporting to this article.