The assembly line, energy plant and retail store have changed dramatically in the past 25 years—and the jobs have, too. Nearly 1 in 5 working Americans has a job that didn’t exist in 1980, many in technology, the fastest-growing segment across all industries. Such rapid change is one reason 6.6 million U.S. jobs are currently unfilled.

Many of these jobs require skills training, but not a college degree. Yet for too long, both the public and the private sectors have failed to develop innovative and effective training programs....