From Technology Review:
“We’re trying to map what the real world looks like onto Facebook so you can run really expressive and powerful queries,” says Mitu Singh, product manager for Facebook’s entities team, a group charged with building a resource called the entity graph.
The entity graph is a little-known companion of Facebook’s famous social graph of around a billion people and 150 billion friend connections. The entity graph describes everything from the restaurants of New York to the concept of philosophy and the connections between those concepts. Singh and colleagues jokingly refer to their work on the entity graph as “project job security,” since mapping every entity in the world is a distant prospect.
Facebook’s most sophisticated tool for tapping into the collective knowledge of its users is an interface called the “places editor.” It guides users to fix errors in or add to the data for places in Facebook’s entity graph; in one mode it allows a person to rapidly click “yes” or “no” buttons to screen for duplicate entries. It might sound dull, but Facebook has found it to be surprisingly popular. “As with Wikipedia, what we’re seeing is people really passionate about their hometown or their current town,” says Singh. “They really like to make sure that it’s fixed and corrected.”
“The Web was designed to provide the backbone of the entity and knowledge graphs that Facebook and Google are building right now,” says Manu Sporny, who chairs the working group at the W3C concerned with RDFa, a technology used—including by Google and Facebook—to add semantic data to Web pages.