Each day, thousands of people from places like Kibera, Africa's largest slum and one of the toughest neighborhoods on earth, commute to an office of Samasource in the east side of Nairobi. The San Francisco-headquartered company occupies four floors of a business park building, with vast banks of computers being used for the job of training data. Google, Microsoft, Salesforce and Yahoo are among the clients of Samasource. What exactly do these people do at Samasource? Its clients won't say, but BBC reports that the "information prepared here forms a crucial part of some of Silicon Valley's biggest and most famous efforts in AI." From the report:

[...] Brenda loads up an image, and then uses the mouse to trace around just about everything. People, cars, road signs, lane markings -- even the sky, specifying whether it's cloudy or bright. Ingesting millions of these images into an artificial intelligence system means a self-driving car, to use one example, can begin to "recognise" those objects in the real world. The more data, the supposedly smarter the machine. She and her colleagues sit close -- often too close -- to their monitors, zooming in on the images to make sure not a single pixel is tagged incorrectly. Their work will be checked by a superior, who will send it back if it's not up to scratch. For the fastest, most accurate trainers, the honor of having your name up on one of the many TV screens around the office. And the most popular perk of all: shopping vouchers.

It's the kind of technological progress that will likely never be felt in a place like Kibera. As Africa's largest slum, it has more pressing problems to solve, such as a lack of reliable clean water, and a well-known sanitation crisis. But that's not to say artificial intelligence can't have a positive impact here. We drove to one of Kibera's few permanent buildings, found near a railway line that, on this rainy day, looked thoroughly decommissioned by mud, but has apparently been in regular use since its colonial inception.

Almost exactly a year ago, this building was the dividing line between stone-throwing rioters and the military. Today, it's a thriving hub of activity: a media school and studio, something of a cafeteria, and on the first floor, a room full of PCs. Here, Gideon Ngeno teaches around 25 students the basics of using a personal computer. What's curious about this process is that digital literacy is high, even in Kibera, where smartphones are common and every other shop is selling chargers and accessories, which people buy using the mobile money system MPesa.