In his 2007 book “Innovation Nation: How America is Losing its Innovation Edge, Why It Matters and What We Can Do to Get It Back,” John Kao writes: “Finns have come to cherish gifted educators as Texans do ace quarterbacks. The country’s teacher training schools have 10 applicants for every opening.” Mr. Barrett, whose company promotes the use of computers in schools, takes a similar view. “PCs aren’t magic,” he said. “Good teachers are.