When Toby Bouska Jr. started assembling cabs for Kenworth semitrucks last year, he learned the ropes by observing longtime workers at the factory. But it wasn't exactly engaging, and he didn't get much practice doing the job himself.

"It's them doing the job, and you just have to watch," said Bouska, 21, who works at Kenworth's plant in Chillicothe. "I'm not really good at just sitting there watching."

But then his managers had him train in a new way: with a high-tech headset. They gave him a Microsoft HoloLens, a device that blends digital imagery with the real world. When