Another problem is that the system the Kinect uses to map the positions of a user’s hands, shoulders, legs, and so forth—although surprisingly accurate—does not achieve especially fine resolution. When it interprets gestures, it sees hands, not fingers. This means that to control the device, a user must wave and make large arm motions.
So long as this is true, an interface such as the Kinect couldn’t be used at a desk. It would be tiring over an extended period of time, and it would also be slow. Compare, for example, the time it takes to scroll down three Web pages with a mouse, which requires tiny flicks of the wrists, with the time it would take to raise and lower the arm three times.
The device is unacceptably slow in other ways as well. To click a button on the screen, for example, the user has to hold a hand still for about three seconds to confirm that a click is intended. Imagine how annoying online shopping would be if there were a three-second delay every time you wanted to take a closer look at something.
These sorts of issues are probably deal killers for gestural interfaces, says Ben Bederson, an associate professor of computer science at the University of Maryland who studies human-computer interaction. “Microsoft deserves a huge amount of credit for the Kinect,” he says. But he adds that the device’s impressive technology is probably suited only to niche applications such as gaming. Even if the quality were as good as possible, he says, there are fundamental issues that he doesn’t believe can be solved: users need speed, accuracy, simplicity, and a comfortable interface that doesn’t interfere with a task or tire you out.
“When Microsoft can address all of those issues with gestures,” he says, “I’m all ears, but I’m not optimistic.”