The federal government has enticed 730 schools across the nation to reinvent themselves this school year, and nearly a third have chosen the most difficult paths to get a piece of the more than $500 million set aside for transforming schools where too many children are failing to learn.

"This is tough, tough work, but it's desperately needed," U.S. Education Secretary Arne Duncan said Thursday.

Most of the schools fired their principals and changed their entire approach to learning this school year, while others replaced much of the staff. Yet Duncan said "there's been no drama about it. Folks have moved with an urgency that's sort of fantastic to watch."

The lack of drama was in sharp contrast to a couple of early school invention efforts, including one in Central Falls, Rhode Island, where a high school's entire teaching staff was fired in February and got their jobs back in May after community protests.

To get federal school improvement money, schools in the bottom 5 percent of those not making adequate yearly progress under the federal No Child Left Behind law must choose from among approaches to turn around student test scores. The program is voluntary.

The approaches include: closing the school and moving kids to other buildings; restarting a traditional public school as a charter school; firing most of the staff and starting over with a new team; or firing the principal and taking a new approach to learning.

Duncan's preliminary report on the success of the program noted that 71 percent of participating schools chose the fourth approach, called transformation.

Another 21 percent replaced the school principal and at least half of the teachers. About 3 percent closed down the school and 5 percent are restarting.

Union leaders said Thursday that the program became less controversial as school district officials started collaborating with teachers instead of blaming them for their problems.

"Our members are excited. They want to make a difference in these schools," said Dennis Van Roekel, president of the National Education Association, the nation's largest teachers union.

Not every school has chosen to involve teachers in their transformation plans, Van Roekel said, but he predicted long-lasting success won't be possible without teacher engagement and collaboration.

Regardless of which improvement model they choose, Van Roekel said success also requires community and parent engagement, effective school leadership, more time for learning and staff collaboration, social services for children, and conditions that attract educators to the most needy schools.

His message to administrators who haven't involved teachers in their planning: "It's never too late."

The school improvement grants are spread across the country and distributed among urban, rural and suburban schools. Of students in the affected schools, 44 percent are African American, 34 percent are Hispanic, 16.5 percent are white, 2.5 percent are Asian and 2.2 percent are Native American.

Nearly half the schools implementing one of the improvement models are high schools, 24 percent are elementary schools, 21 percent are middle schools and 7 percent are some combination of the three.

In two schools in Marysville, Wash., the district initially planned to fire the principal and redesign its education plan. But more than half the teachers at Tulalip Elementary said they didn't have the energy or the time over the summer to make sure their "new" school was ready to open in the fall.

So instead, most of the teachers and principal were replaced — many were moved to other schools.

That made it possible for the school to get more money to pay for the more dramatic change, said Arden Watson, president of the Marysville Education Association.

Tulalip Elementary, which is located on an Indian reservation, now has a strong focus on Native culture.

But the main changes at Tulalip are the same ones taking place at schools across the country: a longer school day, more time for teachers to plan and collaborate, smaller classes, thoughtful examination of student improvement data, onsite professional development, and extra help for students struggling in math and for those behind in reading.

"The work is not easy in any way. We're moving forward, though. We feel like we're on the right path," said Judy Albertson, the district's school improvement facilitator.